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Q&A

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Description

Evergreen, fast-growing tree, up to 12 m height, with single or multi-stemmed trunks, and greenish bark. Leaves are alternate with petioles up to 61 cm long, palmately compound with mostly 7-16 leaflets, these shiny, light green, oblanceolate, up to 30 cm long, and entire margins (or sparsely toothed when young). Flowers are borne in dense clusters that form a large, red, showy inflorescence at stem tips above foliage. Fruits are purplish black, round, fleshy drupes up to 7 mm in diameter (Gilman and Watson, 1994).

Hosts

S. actinophylla has been documented shading out the threatened species nodding pinweed (Lechua cernua) in Florida (Langeland et al., 2008). In addition, seedlings of this species may germinate in the crotches or branches of large trees and in this case the plant will grow as an epiphyte that can strangle and eventually kill host trees (Menninger, 1971).


Source: cabi.org
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Title: Procyon lotor
Description

P. lotor is a medium-sized member of the order Carnivora, with a stocky torso and short limbs. The pelage coloration, with the striking black mask and ringed tail, makes the raccoon easily recognizable. The spine is curved posteriorly, giving the animal a roundish appearance similar to a bear. The black mask usually extends from slightly above the eyes to the base of the snout and flares out along the cheeks. It is accentuated by white lines immediately above and below the mask, and the mask is often broken down the middle by a brown bar. As a raccoon ages the mask tends to fade. The anterior side of the ear is entirely white;the posterior side has a black base that extends to nearly half the ear. The top of the nose and forehead are greyish or reddish brown. Pelage color on the shoulders and back is dominated by reddish-brown guard hairs. However, variations on this color scheme are common, including nearly black, orange, or cinnamon variants, and geographic variation in pelage color occurs (Goldman, 1950;Stains, 1956;Johnson, 1970;Lotze and Anderson, 1979;Gehrt, 2003). The ventral side is lighter, usually a light brown, with sparse guard hairs. The hair on each foot is short and whitish-gray. Four to seven blackish rings and a dark tip characterize the tail. The feet are plantigrade with naked footpads. Front and back feet are pentadactyl with no webbing between the toes, and each toe has a sharp, curved, nonretractile claw. The tracks resemble human prints, with the long toes of the front foot resembling fingers and the shorter toes of the back foot, with its longer foot pad, resembling human toes. The pinnae are relatively small compared to those of canids or felids, and the snout is medium length and pointed. Cheek tufts that flare to the sides give the impression of a broad head when seen from the front. There are no pelage differences between males and females;however, males are larger than females in body measurements and weight. Adult body weights usually range from 4 to 9 kg, with regional variations in size across North America, and body weights may change seasonally at northern latitudes. The smallest individuals occur in South Florida (Goldman, 1950);with mean winter body weights of 2.4 and 2.0 kg for adult males and females, respectively. Mean body weights for adults at northern latitudes range from 6.9 - 10.4 kg during the winter, and body weights in South Texas average 9.0 and 6.7 kg for males and females, respectively (Gehrt and Fritzell, 1999). Adult raccoons have 40 teeth, with a dental formula: i3/3;c1/1;p4/4;m2/2 (Gehrt, 2003). The dentition reflects the omnivorous habits of this species, with sharp incisors and canines suitable for cutting or tearing, contrasting with square-shaped molars and 4 th upper premolars with small, rounded cusps, suited for grinding plant material. Morphological characteristics of P. lotor in Germany appear to be similar to those of North America (Lutz, 1995).


Source: cabi.org
Title: Procyon lotor
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Description

The prominent dark and light banding pattern on the shell is the most obvious characteristic of D. polymorpha. Its specific name, "polymorpha", derives from its many variations in shell colour, pattern and shell shape. The outer covering of the shell (the periostracum) is generally well polished, and light tan in colour with a distinct series of broad, dark, transverse colour bands which may be either smooth or zigzag in shape. Within a population, individual shell colours may range from very light coloured without discernable dark banding to those that are darkly-pigmented overall, obliterating all banding.


Source: cabi.org
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Description

The following description comes from Flora of China Editorial Committee (2015);Trees or erect shrubs, 7-10 m tall. Bark grayish to dark brownish, thick, smooth, branches puberulent when young, later glabrous. Petiole 3-4 cm, leaf blade suborbicular, 10-15 ? 9-14 cm, stiffly papery, abaxially almost glabrous, adaxially glabrous, primary veins 9-11, secondary and higher order veins protruding, base shallowly cordate, apex bifid to 1/3-1/2, lobes slightly acute or rarely rounded at apex. Inflorescence a raceme with few flowers, or a panicle with up to 20 flowers, axillary or terminal. Flower buds fusiform, 4- or 5-ridged, with an obtuse apex. Pedicel 7-12 mm. Calyx open as a spathe into 2 lobes, one with 2 teeth and other 3-toothed. Petals light pink, oblan?ceolate, 4-5 cm, clawed. Fertile stamens 3, filaments ca. as long as petals. Staminodes 5 or 6, 6-10 mm. Ovary stalked, velvety, style curved, stigma slightly enlarged, peltate. Legume linear, flat, 12-25 ? 2-2.5 cm, valves woody. Seeds compressed, sub?orbicular, 12-15 mm in diameter.


Source: cabi.org
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Description

S. taccada is a dense, multi-stemmed shrub that generally grows up to 3 m in height. Leaves are light green, succulent, with a waxy covering and are alternately arranged along the stem. Blades are elongated and rounded at the tips, 5 to 20 cm long and 5 to 7 cm wide. Flowers are white, often with purple streaks, 8 - 12 mm long, and have a pleasant fragrance. They have an irregular shape with all 5 petals on one side of the flower making it appear to have been torn in half. Flowers grow in small clusters from the leaf axils near the ends of the stems. Fruits are white fleshy berries about 1 cm long. Seeds are beige, corky, and ridged (Wagner et al., 1990).


Source: cabi.org
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Description

W. sinensis is a woody, deciduous vine that can climb to 20 m. The bark on older vines is dark grey with light colored dots (lenticels). Vines twine clockwise (left to right). Leaves are alternate and compound with 7-13 leaflets. Leaflets are attached opposite to each other along the leaf stalk. Leaflets have wavy edges and long, tapering tips. Young leaves are densely covered in silky hairs, but are almost hairless when mature. Grape-like clusters of fragrant lavender to purple flowers hang from the vines, usually flowering as the leaves emerge in spring. Flowers are attached to the cluster by a short stalk. Pubescence on the flower is conjoined to the upper third of inner face of the standard (or banner) petal. Flower clusters (racemes) are 12Ð35 cm long. Flattened pods 6-15 cm long and 2-3 cm wide are velvety. Pods contain 1 to 8 flat, round, brown seeds each 1.2-2.5 cm in diameter (Trusty et al., 2007a;Miller et al., 2010).


Source: cabi.org
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Description

Upper parts dark brown with light golden brown tips, under parts light grey. The tail is dark grey/brown. Crown hairs are directed backwards, sometimes forming a short crest on the mid-line. Skin is black on the feet and ears, and the muzzle is light greyish-pink. Eyelids often have prominent white markings, and white spots are sometimes seen on the ears. No perineal swelling. Males 3.5kg - 8.3kg, Females 2.5kg - 5.7kg.


Source: cabi.org
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Description

Annual herb 0.3Ð2.5 m high, with a weak taproot. Stems erect, branched, glabrous or sparsely hispid. Leaves cauline, alternate, deeply lobed, petioles 10Ð70 mm long, blades 100Ð200 mm long, ultimate lobes 2Ð10 mm wide, margins spinulose-ciliate, apices acute, often mucronulate. Synflorescences 100Ð300 mm long, spreading with linear-subulate bractlets 6Ð10 mm long, apices acuminate. Capitula 5Ð15 mm diam., involucral bracts erect, oblong-lanceolate, 7Ð11 mm long with apices acute to obtuse apices, ray florets rose-pink to purple, laminae oblong-oblanceolate, 5Ð15 mm long with obtusely 3-lobed apices, disc florets 5Ð6 mm long. Cypselae light brown, 12Ð35 mm long, glabrous or scabridulous proximally, setose distally, pappus 2Ð3 widely divergent to reflexed awns 3Ð5 mm long (description compiled from Pruski 1997, Beentje and Hind 2005, Kiger 2006, Puttock pers. obs.).


Source: cabi.org
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Description

Kudzu is a perennial climbing vine that produces very large tubers up to 2 m long and 18-45 cm wide that can weigh as much as 180 kg on old plants. Stems or branches are strong, approximately 0.6-2.5 cm in diameter and up to 30 m in length. They can grow up to 25 cm per day or 18 m per growing season, and produce root crowns where nodes contact soil. Leaves are pinnately trifoliate, 8-20 cm long and 5-19 cm wide with leaflets ovate to orbicular and unlobed to trilobed. Leaves are pale green above and light to greyish green below. Purple to blue flowers, that smell of grapes, are borne on a mostly unbranched inflorescence 10-25 cm long. Seeds are borne in golden-haired, brown, flattened, oblong pods, 4-13 cm long and 0.6-1.3 cm wide. The seeds, visible through the pod, are flattened, ovoid and reddish brown with a black mosaic pattern. They are approximately 4-5 mm long by 4 mm wide and 2 mm thick (van der Maesen, 1985). For a more detailed description and a key to the three varieties, see van der Maesen (1985).


Source: cabi.org
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Description

T. capensis is a clambering or semi-erect shrub, 3-4 m in length. Stems cylindrical, lenticellate, puberulous;cross section of the mature stem with peripheral phloem not forming a cross. Leaves opposite, imparipinnate, 7-11-foliolate, without tendrils;leaflets 1.5-4.2 ? 1-3 cm, elliptical to sub-rounded, membranaceous, sessile, the apex rounded, the base rounded or abruptly cuneate, the margins serrate;upper surface dull, pale, with slightly prominent venation;lower surface light green, dull, punctate, with slightly prominent venation, forming a conspicuous network, with tufts of hairs in the axils;petioles 1.5-2.5 cm long;pseudo-stipules absent. Flowers numerous in axillary racemes;pedicel 6-10 mm long. Calyx green, 5-7 mm long, 5-dentate, ciliate, puberulent;corolla orange or reddish orange, tubular, curved, 3.5-5 cm long, with 5 oblong, unequal lobes, the 2 upper lobes smaller than the 3 lower;stamens 4, of equal length;ovary superior, oblong, glabrous. Capsule linear, 5-11 cm long and 7-8 mm wide;seeds in 2 rows, slender, 2-winged, the wings hyaline-membranaceous (Acevedo-Rodr’guez, 2005).


Source: cabi.org
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Description

J. mimosifolia is a medium to large tree 5-15 m tall, up to 20-25 m on favourable sites, deciduous and with an attractive spreading crown. Bark is thin and grey-brown. Twigs are slender, somewhat zig-zag and light reddish-brown in colour. Leaves are bipinnately compound and 15-30(-40) cm long, with 13-31 pinnae, each with 10-41 sessile leaflets, (3-)5-10(-12) mm long and (1-)2-3.5(-4) mm wide, oblong, glabrous or slightly puberulent along the midrib and margins. Flowers are described variously to be blue-violet, lilac, lavender-blue or mauve in colour. They occur in open, terminal panicles, the branches puberulent, calyx reduced, broadly campanulate, 5-toothed, the teeth around 1 mm long;corolla purplish blue, the tube white within, 2.4-5.2 cm long, 0.7-1.2 cm wide at the mouth, pubescent externally and within at the level of the stamens. Capsules drying reddish brown, compressed-orbicular, 3.2-5.8 cm long, apex often shallowly emarginate, base truncate to subcordate. Seeds 0.9-1.2 cm long, each surrounded by a thin membrane acting as a wing, more or less surrounding the seed body (PIER, 2014).


Source: cabi.org
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Title: Ficus pumila
Description

The juvenile phase of this plant is morphologically different from the adult phase. Juvenile plant attaining several metres in length, much branched, climbing by means of adventitious roots, stems flattened, leaves 1.5-2.5 cm long, ovate to oblong, retuse at the apex, very closely spaced. Adult plant developing into a much branched liana, with adventitious roots, attaining 10 m in length, produces abundant white latex when wounded. Stems flattened, striate, tomentose, glabrescent when mature, with short pendulous branches. Leaves alternate, simple, 4-7 ? 2.2-4 cm, oblong, oblanceolate, ovate, or elliptical, the apex obtuse, the base subcordiform, the margins entire, upper surface dark green, slightly shiny, with the venation notably lighter, lower surface light green, dull, with prominent reticulate venation, petioles 1.3-1.6 cm long, flattened on the upper surface, pubescent, light brown, stipules oblong-lanceolate to subulate, persistent, 1-1.2 cm long, brown, sericeous. Syconium green, pyriform, up to 6 cm long, soft (Acevedo-Rodriguez, 2005).


Source: cabi.org
Title: Ficus pumila
Light
Description

The following description is adapted from Morton (1987): S. cumini may reach 30 m tall in India and Oceania or up to 12Ð15 m in Florida, USA, with a broad crown up to 11 m in diameter and a trunk diameter of 0.6Ð0.9 m though it usually has a multi-stemmed form branching close to the ground. Bark is rough, cracked, flaking and discoloured on the lower part of the trunk, becoming smooth and light-grey higher up. Evergreen leaves have a turpentine smell, and are opposite, 5Ð25 cm long, 2.5Ð10 cm wide, oblong-oval or elliptic, blunt or tapering to a point at the apex;pinkish when young, becoming leathery, glossy, dark-green above, lighter beneath, with a conspicuous, yellowish midrib when mature. Flowers are fragrant and appear in clusters 2.5Ð10 cm long, each being 1.25 cm wide and 2.5 cm long, with a funnel-shaped calyx and 4Ð5 united petals, white at first, becoming rose-pink, shedding rapidly to leave only the numerous stamens. Fruit appear in clusters of just a few or 10Ð40, are round or oblong, often curved, 1.25Ð5 cm long, turning from green to light-magenta, then dark-purple or nearly black, although a white-fruited form has been reported in Indonesia. The skin is thin, smooth, glossy, and adherent. The pulp is purple or white, very juicy, and normally encloses a single, oblong, green or brown seed, up to 4 cm long, though some fruits have 2Ð5 seeds tightly compressed within a leathery coat, and some are seedless. The fruit is usually astringent, sometimes unpalatably so, and the flavour varies from acid to fairly sweet.


Source: cabi.org
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Description

O. eperlanus is a small to medium-sized fish whose adult size varies greatly according to habitat (Nellbring, 1989;Maitland, 2000;Davies et al., 2003;Kottelat and Freyhof, 2007). The normal range in length is 10-20 cm but some fish reach 30 cm. In general, fish from non-migratory freshwater populations are much smaller than those which have lived in the sea. It is a slender fish with large scales and eyes, a large mouth with a projecting lower jaw and obvious teeth on both jaws. It has a fleshy adipose fin between the dorsal and tail fins. Dorsal soft rays: 9-12;anal soft rays: 12-16;vertebrae: 55-62 (Froese and Pauly, 2012). Dorsal side light olive green, flanks silver stripe, belly creamy white (Froese and Pauly, 2012).


Source: cabi.org
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Description

F. moluccana is a medium to fairly large-sized tree up to 40 m high with a small buttress. The bole is branchless up to 20 m and up to 100 cm or more in girth and in dense stands is generally straight and cylindrical. When grown in the open, trees form a large canopy, which is umbrella shaped. In plantations of 1000-2000 trees per ha the crowns become narrow. The bark is light grey with warts, inner bark smooth and pink though young parts may be densely reddish brown tomentose or puberulent. Leaves alternate, bipinnately compound and 20-40 cm long with 4-(10-12)-15 pairs of pinnae, each pinnae 5-10 cm long containing 8-(15-20)-25 falcate leaflets 10-20 mm long and 3-6 mm wide, pubescent, dull green above, paler below, obliquely elliptic, falcate, midrib strongly excentric near one of the margins. Leaves each have a large nectary below the lowermost pair of pinnae and smaller ones between or below most pairs of pinnae. Flowers are large, branched, bell-shaped, in paniculate axillary racemes ca 20 cm in diameter, often with 2 serial branches from 1 bract scar;calyx 1-1.5 mm long, silky pubescent, the teeth 0.5 mm long. The flowers are bisexual, regular and 5-merous. The corolla is creamy-white to greenish-white and sericeous 3-4.5 mm long (excl. stamens);stamens 10-17 mm long, numerous and extend beyond the corolla. Pods are narrow and flat, densely pubescent or glabrous, green turning brown and splitting on maturity, 10-13 cm long and 1.5-2.5 cm wide, winged along ventral suture with many (ca. 20) transversely arranged, ellipsoid, flat dark brown seeds, 5-7 mm long, 2.5-3.5 mm wide.


Source: cabi.org
Light
Description

Tree to 15 m high (50 feet) with the fused conical stipules enclosing the step tip, sap milky. Leaves simple, alternate, blade ovate to elliptic, 4-12 cm long (1 5/8-5 in), typically light green, finely veined, with a sharp or attenuate tip. Fruits can be found on the tree throughout the year. Fruit an orange, red, pink, or purple, subglobose synconium 7-12 mm long (1/4-1/2 in), paired in the leaf axils. [Taken from Whistler, 2000]


Source: cabi.org
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Description

The habit of C. laevigatus is a tree growing 15-20 m tall, often with a strong leader. Trunks have a dbh (diameter at breast height) of 60 cm (Dawson and Lucas, 2011), though the largest trunk recorded was 300cm (Stowe, 2003). Bark of mature trees is dark brown, corrugated, with the whitish corrugations fractured into sections about 1x3 cm, by 0.5 cm thick. Bark of younger trees is light brown, and marked, often with short horizontal bands, like sewing stitches. Branches are stout to 3 mm thick, even in young shoots, with raised, roundish leaf scars. Strong sprouts can form on damaged trunks.


Source: cabi.org
Light
Description

C. arizonica is a medium sized evergreen tree growing 5-25 m tall. It has a conical crown when young, becoming broadly columnar with age. The reddish-brown to gray bark peels in thin strips or plates becoming furrowed with age. C. arizonica var. glabra has smooth bark. Scale-like needles are dusty green to gray green, sometimes silvery, and are arranged opposite in pairs tightly clasping cord-like or four sided twigs. Cones are reddish brown to gray, somewhat round with 6-8 shield-shaped woody scales, 10-25 mm wide (USDA-NRCS, 2006;SEINet, 2017). Seeds are light tan to dark brown, 4-8 mm long (SEINet, 2017).


Source: cabi.org
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Description

The following description is from Flora of North America Editorial Committee, 2015;Perennials, 6Ð65+ cm (usually rhizomatous, sometimes stoloniferous). Stems 1(Ð4), erect, simple or branched, densely lanate-tomentose to glabrate. Leaves petiolate (proximally) or sessile (distally, weakly clasping and gradually reduced), blades oblong or lanceolate, 3.5Ð35+ cm ? 5Ð35 mm, 1Ð2-pinnately lobed (ultimate lobes ± lanceolate, often arrayed in multiple planes), faces glabrate to sparsely tomentose or densely lanate. Heads 10Ð100+, in simple or compound, corymbiform arrays. Phyllaries 20Ð30 in ± 3 series, (light green, midribs dark green to yellowish, margins green to light or dark brown) ovate to lanceolate, abaxial faces tomentose. Receptacles convex, paleae lanceolate, 1.5Ð4 mm. Ray florets (3Ð)5Ð8, pistillate, fertile, corollas white or light pink to deep purple, laminae 1.5Ð3 ? 1.5Ð3 mm. Disc florets 10Ð20, corollas white to grayish white, 2Ð4.5 mm. Cypselae 1Ð2 mm (margins broadly winged).


Source: cabi.org
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Description

A highly variable species, S. murinus varies widely in colour, size and weight. It is small, secretive and mouse-like with a long pointed nose. The fur is short and velvety, ranging in colour from light grey-brown to black and recorded adult weights vary between 23.5g to 82.0g in females and 33.2g to 147.3g in males (Ruedi et al., 1996). The head-to-body length of S. murinus is up to 15cm, the tail length up to 8cm (Baker, 2005). A study comparing shrew populations from Guam and Madagascar showed some significant differences in appearance, body weight and length, with female shrews from Madagascar being heavier than females from Guam (Hasler et al. 1977). Chang et al. (1999a,b) found that the average weight of adult females in Taiwan was 37.4g, and the average weight of juvenile females was 23.2g, while the average weight of adult males was 58.6g, and the average weight of juvenile males was 32.9g. Musk shrews have very small eyes, thick, relatively hairless tails and make frequent shrill high pitched squeaks. The musk glands on its flanks give it a distinctive smell (BBC, 2006).


Source: cabi.org
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Description

C. papyrus is a large, emergent, aquatic perennial, producing short rhizomes covered in thick, black scales. The roots are tough, extending 1 m or more in suitable substrate. Rootlets are numerous. Culms are erect, up to 5(-9) m tall, 5-6 cm or more (15 cm or more;Ludwig Triest, personal observation, 2015) across at the base (widest point), smooth, trigonous (angles very rounded, particularly on lower parts) and green (photosynthetic), spreading when old. The pith is solid, white-light brown;vascular bundles prominent. Leaves are reduced, sheathing and restricted to the basal 50 cm or so of the culms. They are tough, reddish-blackish brown when young, expanding with age, the coloration restricted to lateral edges sub-marginally;margins scarious, becoming papery. Colours fade and sheaths split ventrally with age.

Biological Control
Zambian Alien Invasive Species (2014) claims that Òbiological control of papyrus can be achieved by the production of toxin from a novel fungal isolate. The novel isolate, Dactylaria higginsii [ Pseudopyricularia higginsii ], can be grown, and the toxins recovered by the techniques which are well known to those skilled in the art. The fungus can be used to directly and specifically deliver its phytotoxin composition to papyrus. This is delivered to the plant by applying an effective amount of the biologically-active fungus directly to the plant. The fungus produces sufficient quantities of a phytotoxin compound to inhibit the growth, or actually induce mortality of papyrus. The growth of the fungus can also mechanically disrupt nutrient transport in the vascular system of the plant.Ó This material has been developed as a bioherbicide for the control of weedy sedges like purple nutsedge (Cyperus rotundus) (Kadir and Charudattan, 2000) but there seems to be no confirmed evidence of its effectiveness on C. papyrus.

Source: cabi.org
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Description

In Australia, C. equisetifolia subsp. equisetifolia is mainly a small tree, 8-16 m tall, in contrast to populations in South-East Asia where the tree may attain heights of 35 m with diameters to 50 cm. The subsp. incana is typically a small tree and may be reduced to only a large shrub 6-10 m tall on poor sites. Form in wild populations is very variable, varying from crooked, low branching trees on exposed sea shores, to straight-stemmed forest trees in more sheltered situations. Crowns are finely branched. The bark is light grey-brown, smooth on small trunks, becoming rough and thick furrowed on older trees. Encircling bands of lenticels are prominent on young bark. The inner bark is reddish and astringent (Doran and Turnbull, 1997). Twigs are drooping, needle-like, furrowed, 1-2.5 mm in diameter and 23-38 cm long and angular to rounded in cross-section, glabrous or pubescent. The minute teeth-like reduced leaves are in whorls of 7-8 per node. Male flowers occur on simple terminal, elongated spikes 7-40 mm long and are arranged in whorls with 7-11.5 whorls per cm of spike. Female flowers are borne on lateral woody branches. The 'cones' are globose to short- to long- cylindrical, 10-35 mm long, 9-15 mm diameter, with acute bracteoles more or less protruding from the surface of the cone. Fruitlets bear a single, dull brown samara 6-8 mm long. In subsp. incana the young shoots and 'cones' are frequently covered in a fine white pubescence.


Source: cabi.org
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Title: Sechium edule
Description

A monoecious, vigorous, perennial herbaceous vine with a large tuberous root. Stem climbing or sprawling, longitudinally grooved, growing 10-15 m in a single season. Tendrils large, 2- to 5-branched. Leaves simple, spirally arranged, petiole 3-25 cm long, leaf-blade broadly ovate-circular in outline, 7-25 cm in diameter, base deeply cordate, 3- to 7-angular or lobed, acute, margins obtusely dentate, scabrid hairy. Inflorescences axillary racemes with small, greenish or cream, 5-merous flowers, hypanthium saucer-shaped, with 10 pouch-like nectaries on the bottom, male racemes with peduncle 6-30 cm long, 10- to 30-flowered, stamens 5, filaments united, female flowers usually solitary on short pedicels, in same axil as male, corolla ca. 2 mm in diameter, connate style and stigmas, forming a small head. Fruit a one-seeded fleshy berry, variable, commonly pear-shaped, 7-20 cm long, somewhat ribbed, smooth or shortly spiny, dark green to almost white, fruit stalk 2-3 cm long, pendent, pulp white or greenish-white. Seed solitary, ovoid to ellipsoid, 2.5-5 cm long, compressed, white, germinating within the fruit, usually while the fruit is still attached to the plant, in some genotypes seed-coat with fibres radiating into the flesh, in others obsolescent and the flesh fibreless.;Other botanical information: The genus Sechium P. Browne has long been considered as monotypic with S. edule as the only species. Since the 1970s wider genus concepts have been proposed, including 3-9 species, all indigenous to Central America. S. compositum (Donn. Smith) C. Jeffrey, occurring in southern Mexico and in Guatemala, is considered the closest wild relative of S. edule. Its fruit is bitter and it bears spines along its 5-10 ridges. Chayote cultivars do not breed true, although it has been observed that cultivars do not segregate significantly from one generation to the next because of the relative isolation of chayote plants from one another when planted in home gardens. When planted together, complete panmixy can be observed. Substantial efforts made at CATIE (Costa Rica) to describe cultivars on the basis of fruit characteristics proved to be of limited relevance because of the extraordinary variability, with continuous variation in almost all the characters. The variable fruit characters include size (7-20 cm long), weight (100-1000 g), colour (continuous range from white to dark green), shape, fruit-wall features (spines, lenticels, grooves and ridges), flavour and texture. Nevertheless, farmers 'classify' the genotypes by a combination of such fruit characteristics. Instead of speaking of cultivars, it seems best to consider those types as landraces or as primitive populations. At least 25 landraces exist in Central America. Commercially grown chayote consists of two types: a medium sized, light-green, smooth, pear-shaped fruit and a small, white, smooth, globular one. Several types can be distinguished in South-East Asia. For example, in West Java (Indonesia) the common type is dark green and almost glabrous, but more spiny and lighter green types can be found. A complete white type, less tender and spiny, is sometimes grown as a botanical curiosity.


Source: cabi.org
Title: Sechium edule
Light
Description

B. pilularis is an evergreen shrub, often 1-3 m in height (Steinberg, 2002);leaves are sessile or short petiolate with blades oblanceolate to obovate with three principal veins and in alternate leaf arrangement (Flora of North America Editorial Committee, 2015). There is a well-developed taproot of up to 3 m and lateral roots are also well developed (Steinberg, 2002). Inflorescences in paniculiform arrays (Flora of North America Editorial Committee, 2015) and made up of small whitish (female) to yellowish (male) flowers. Female flowers are discoid without ray florets (Steinberg, 2002). They are 0.4-0.63 cm long, and clustered at branch tips or in leaf axils. Male flowers are slightly smaller. Achenes are 0.1-0.2 cm long with a 0.6-1 cm long pappus (Munz, 1973;Hickman, 1993). Plants are dioecious with male plants flowering before the females. Achenes are small with long pappus. Seeds are very light (Steinberg, 2002).


Source: cabi.org
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Description

R. harrisii is a small euryhaline crab 26 mm carapace width) which belongs to the family Panopeidae (mud crabs). Descriptions of the crab in its native range are provided in Rathbun (1930), Ryan (1956), Christiansen (1969), Williams (1984), and Galil et al. (2002) and are summarized below. The carapace is subquadrate and greatest in width at the fourth pair of lateral teeth, which line its sides below the eyestalks. The carapace is transversally and latitudinally convex. The front is slightly notched with its margin transversally grooved, appearing double when viewed from the front. The lateral teeth are not prominent and the first and second teeth are fused. The third, fourth and fifth teeth are blunt, pointing obliquely upward. The maleÕs abdomen has five segments: the third segment does not reach the coxae of the last pair of walking legs and the terminal segment has a rounded tip. The chelae are unequal in size and dissimilar. The major chela has a short fixed carpus and a strongly curved dactyl. The dactyl has a moderately developed basal tooth. The carpus has a subdistal groove and a tooth at an inner angle. The upper surface of the carpus is granular in juveniles, but smooth in adults. The walking legs are long, slender, compressed and somewhat hairy. The antennules have black chromatophores. The crab is generally brownish-green in colour with maroon blotches, but is often stained with bottom mud. The chelae are light at the tips with spots on the upper surface.


Source: cabi.org
Light
Description

Detailed accounts of the physical features of I. punctatus can be found in the texts by Moyle (1976), Becker (1983) and Etnier and Starnes (2001). The adult channel catfish is blue, olive, grey or black on the upper part of its body, with dark spots along the flank and a white ventral surface. The colour appears to be dependent on the colour of the water it inhabits. In clear water it may appear almost black, while in muddy water it may be olive to a light yellowish-white. Young channel catfish have dark spots on their sides, the spots tending to fade or disappear in adults. Very large or very small individuals have fewer spots or lack them altogether. The channel catfish has a stout, cylindrical body with a broad flattened head and large terminal mouth, the upper jaw extending or protruding beyond the lower jaw. It has eight long and unequal barbels around its mouth, 4 are on the chin, 2 on the snout and one in both corners of the mouth. It has a scale-free slimy body, an adipose fin and a deeply forked tail, with the top of the fin being larger than the rounded bottom portion. This deeply forked tail distinguishes the channel catfish from other catfishes except the blue catfish (I. furcatus). The dorsal and pectoral fins have spines while the curved anal fin has 24-29 rays. Taste buds are present on the interior of the mouth and over the body. Males generally have larger heads and a darker coloured body than females.


Source: cabi.org
Light
Title: Morus alba
Description

A small to medium tree growing up to 15 m, M. alba has a short trunk, and a rounded crown with a dense canopy of spreading branches. Leaves are alternate, simple, 6-18 cm long, 5-13 cm wide, broadly ovate, dentate or lobed with 3 prominent veins running from the rounded or obliquely cordate base. Somewhat polymorphic, leaves are shiny green on the adaxial surface, paler and slightly hairy underneath. Bark is light brown to grey, smooth but may be furrowed. Dioecious, male inflorescences are small with 4 stamens, filaments inflexed in bud, green and borne on long catkins. Female flowers are inconspicuous, perianth with 4 free or almost free segments, aggregated in short spikes. Fruit is an ovoid or cylindrical syncarp composed of achenes, pendunculate, red when immature, blackish-purple, purple or greenish-white when mature, 1-2.5 cm long (Global Invasive Species Database, 2016, Tutin, 1964).


Source: cabi.org
Title: Morus alba
Light
Description

G. physocarpus is an upright, soft shrub 0.5 to 2 m tall with a fibrous rootstock. Young stems and inflorescences pubescent. Petiole approximately 1 cm;leaf blade narrowly lanceolate, 5-l0 ? 0.6-1.5 cm, adaxially sparsely pubescent, abaxially hairy along midvein, both ends tapering or acute. Branches are pale yellowish green and hollow. The leaves are light green, opposite, and narrowly oblong to lance-shaped. Flowers in pendulous clusters, corolla white, 1.4-2 cm in diameter;lobes ovate, 8-10 mm, reflexed, margin densely bearded. Corona lobes white, inner margin of hoodlike apex with 2, short, recurved or straight cusps, with a large adaxial nectary. In the centre of the flower is the corona, consisting of five pouched lobes that develop from the petals. The petals are white and the corona is suffused with pink or purple. The corona surrounds the stamens and carpels composed of ovary, style and stigma. The filaments of the stamens are fused to form a staminal column which encloses the female part. The female part consists of two free carpels, the tips of which are united and enlarged to form the style head. This is the yellowish, 5-lobed disc that can be seen at the centre of the flower. The anthers are fused to the style head. The pollen grains of each anther lobe are united to form two waxy masses known as pollinia or pollen sacs. Fruits are large spherical inflated follicles, 6-8 ? 2.5-5 cm, base oblique, apex rounded, beakless;pericarp with soft bristles or spines, minutely tomentose when young, glabrescent when ripe. Seeds ovate, approximately 5 mm;coma shining white, approximately 5 mm, each with a tuft of long silky hairs attached at one end (Notten, 2010;Flora of China Editorial Committee, 2014).

Hosts

G. physocarpus was recorded growing as a weed in pastures and in crops such as sugarcane (Motooka et al., 2003;Flora of China, 2014). It is also an environmental weed affecting principally lowland dry forests, coastal forests and wetlands (DAISIE, 2014;PROTA;2014;USDA-ARS, 2014).


Source: cabi.org
Light
Description

R. oleracea grows up to 40 m tall, with a distinctive, solitary, light gray, erect, cylindrical trunk up to 22 m. Its appearance has been described to be like a marble column (Zona, 1996). Leaves are in the crown at the top of the stem. Flowers are borne in large stalked panicles revealed when the leaf-sheaths beneath them drop off;abundant blue-violet fruit are small, obovoid and without stalks. The fruits turn purplish-black when ripe (Palmpedia, 2014). The roots can often be seen emerging from the stem just above the soil level. Individual trees have 16-22 or 20-22 leaves, 3-5 m long with leaflets of about 1 m in two horizontal ranks;leafstalks about 1.5 m long, broadening to surround and sheath stem Leaf segments are arrayed in two planes on either side of the rachis, however, in the past there was some disagreement in the literature on this characteristic. The species is noteworthy and relatively easy to identify for several reasons, one being that the leaves of the crown typically do not hang much below the horizontal, unlike other species in which the leaves droop and obscure the shaft of the crown. The species is also distinguished within its genus for an unopened peduncular bract which is strongly clavate with an acuminate tip. Groups of rachillae are undulate, forming wavy curves with amplitudes of 4 cm or more (Zona, 1996).


Source: cabi.org
Light
Description

M. zapota is an evergreen, slow-growing tree, 5-20 m in cultivation but reaching up to 40 m in height in the forest, with an average trunk diameter of 1.5 m. The crown is pyramidal to rounded. Branches are horizontal or drooping. Leaves are 5-13 cm long with pointed ends, stiff and alternate, clustering at ends of shoots, pinkish upon emergence, turning light green, then darkening with age. Flowers are inconspicuous, bell-shaped, and white, 0.9 cm in diameter and borne singly or in clusters in leaf axils near the tips of branches. The fruit is a berry, round to oval or conical, 5-10 cm in diameter, weighing 100 to 400 g (some cultivars weigh up to 1 kg).. Fruits mature year-round, but most abundantly from May to September. They are covered with a hairy, brown peel and have very sweet, light-brown to reddish-brown pulpy flesh, gritty to smooth in texture. Each fruit has 0-12 flattened, shiny, black seeds, each 1.9 cm in diameter. Larger trees have red-brown bark with a flaky appearance. A milky latex which exudes from all tree parts coagulates into ÒchicleÓ, the principal constituent of chewing gum before the advent of synthetics (Balerdi et al., 2013;Kaufman and Kaufman, 2013).


Source: cabi.org
Description


Phenotypic Characteristics
X. citri is a Gram-negative, straight, rod-shaped bacterium measuring 1.5-2.0 x 0.5-0.75 µm. It is motile by means of a single, polar flagellum. It shares many physiological and biochemical properties with other members of the genus Xanthomonas. It is chemoorganotrophic and obligately aerobic with the oxidative metabolism of glucose. Colonies are formed on nutrient agar plates containing glucose and are creamy-yellow with copious slime. The yellow pigment is xanthomonadin. Catalase is positive, but Kovacs' oxidase is negative or weak;nitrate reduction is negative. Asparagine is not used as a sole source of carbon and nitrogen simultaneously;various carbohydrates and organic acids are used as a sole source of carbon. Hydrolysis of starch, casein, Tween 80 and aesculin is positive. Gelatine and pectate gel are liquefied. Growth requires methionine or cysteine and is inhibited by 0.02% triphenyltetrazolium chloride. Biovars may be distinguished by utilization of mannitol. For further information on the bacteriological properties of X. citri, see Goto (1992).
Strains of groups B, C and D have many properties in common with group A, the differences being detected by the utilization of only a few carbohydrates (Goto et al., 1980).
Molecular Characterization
Features of citrus-attacking xanthomonads including X. citri and the genus Xanthomonas as a whole, have been characterized at the molecular level for the development of quick and accurate methods for reclassification and identification. The procedures include DNA-DNA hybridization (Vauterin et al., 1995), genomic fingerprinting (Lazo et al., 1987), fatty acid profiling (Yang et al., 1993), SDS-PAGE (Vauterin et al., 1991) and isoenzyme profiles (Kubicek et al., 1989) and monoclonal antibodies (Alverez et al., 1991).
Bacteriophages
Phage-typing is applicable to X. citri with greater reliability than any other plant pathogenic bacterium investigated so far. Many strains of X. citri are lysogenic (Okabe, 1961). Two virulent phages, Cp1 and Cp2, can infect 98% of the strains isolated in Japan (Wakimoto 1967). Similar results were also obtained in Taiwan (Wu et al., 1993). The filamentous temperate phages and their molecular traits have been studied in detail (Kuo et al., 1994;Wu et al., 1996). Phage Cp3 is specific to the canker B strains (Goto et al., 1980). No phages specific to canker C and D strains have been isolated.

Recognition


Methods of detecting X. citri from natural habitats include leaf-infiltration, bacteriophage, fluorescent antibody and ELISA (Goto, 1992). The polymerase chain reaction and dot blot immunobinding assay (DIA) were developed for rapid, sensitive, and specific detection of the pathogen. The detectable limits were reported to be around 30 c.f.u./ml for the former and 1000 c.f.u./ml for the latter (Hartung et al., 1993, 1996;Wang et al., 1997;Miyoshi et al., 1998).

Symptons


Canker lesions begin as light yellow, raised, spongy eruptions on the surface of leaves, twigs and fruits. The lesions continuously enlarge from pin-point size over several months and can be of many different sizes based on the age of the lesion. As the lesions enlarge, the spongy eruptions begin to collapse, and brown depressions appear in their central portion, forming a crater-like appearance. The edges of the lesions remain raised above the surface of host tissue and the area around the raised portion of the lesion may have a greasy appearance. The lesions become surrounded by characteristic yellow halos. Canker lesions retain the erupted and spongy appearance under dry conditions, such as in a greenhouse;whereas they quickly enlarge and turn to flat lesions with a water-soaked appearance with frequent rain. Canker lesions vary in maximum size from 5 to 10 mm, depending on the susceptibility of the host plant. The symptoms are similar on leaves, fruit and stems.
Canker lesions are histologically characterized by the development of a large number of hypertrophic cells and a small number of hyperplastic cells. At an early stage of infection, the cells increase in size and the nuclei and nucleoids stain more easily;there is also an increase in the amount of cytoplasm synchronized with rapid enlargement. However, these hypertrophied cells do not divide;cell division is only detected in the peripheral areas of lesions adjacent to healthy tissue.
The lesions of canker B, C and D are similar in appearance and histology to those of canker A (Goto, 1992).
Reddy and Naidu (1986) reported canker lesions on roots;however, this has not been confirmed.

Impact

X. citri is a bacterial pathogen that causes citrus canker - a disease which results in heavy economic losses to the citrus industry worldwide either in terms of damage to trees (particularly reduced fruit production), reduced access to export markets, or the costs of its prevention and control. Lesions appear on leaves, twigs and fruit which cause defoliation, premature fruit abscission and blemished fruit, and can eventually kill the tree. It is introduced to new areas through the movement of infected citrus fruits and seedlings, and inadvertent re-introduction is highly likely despite the quarantine restrictions that are in place in many countries. Locally, X. citri is rapidly disseminated by rainwater running over the surfaces of lesions and splashing onto uninfected shoots;spread is therefore greatest under conditions of hight temperature, heavy rainfall and strong winds. Some areas of the world have eradicated citrus canker, others have on-going eradication programmes, however, this pathogen remains a threat to all citrus-growing regions.

Hosts


The Citrus species listed in the table of hosts, and the following hybrids, are natural hosts of X. citri, with varying degrees of susceptibility to X. citri. In addition to host plant, susceptibility is also affected by the plant part affected, whether leaves, fruits or twigs. Reddy and Naidu (1986) reported canker lesions on roots but this has not been confirmed.
Hybrids:
C. aurantiifolia x Microcitrus australasica (Faustrime), C. limon x M. australasica (Faustrimon), C. madurensis x M. australasica (Faustrimedin), C. sinensis x Poncirus trifoliata (Citrange), C. paradisi x P. trifoliata (Citrumelo) (Schoulties et al., 1987), C. aurantifolium x P. trifoliata (Citradia), C. nobilis x P. trifoliata (Citrandin), C. unshiu x P. trifoliata (Citrunshu), Citrange x P. trifoliata (Cicitrangle), C. adurensis x Citrange (Citrangedin), C. deliciosa x Citrange (Citrangarin), C. unshiu x Citrange (Citranguma), Fortunella margarita x Citrange (Citrangequat), F. japonica x C. aurantiifolia (Limequat), C. maxima x C. aurantiifolia (Limelo), C. madurensis x C. aurantiifolia (Bigaraldin), C. maxima x C. sinensis (Orangelo), F. margarita x C. sinensis (Orangequat), C. nobilis (Clementine) x C. maxima (Clemelo), C. nobilis (King of Siam) x C. maxima (Siamelo), C. unshiu x C. maxima (Satsumelo), C. deliciosa x C. maxima (Tangelo), C. nobilis (King of Siam) x C. sinensis (Siamor), C. deliciosa x C. madurensis (Calarin), C. unshiu x C. madurensis (Calashu). C. aurantiifolia x F. marginata is immune (Reddy, 1997).
Other than Citrus species and their hybrids, most plants, except P. trifoliata, are not sufficiently susceptible to X. citri under natural conditions to warrant attention as hosts of the bacterium. Although the potential of these plants as natural hosts seems to be negligible, further investigation is necessary because no confirmative host surveys have been undertaken since the 1920s. Species names within the genus Citrus also merit some attention due to their inconsistent use by authors.
Plants other than Citrus spp.:
Unless otherwise stated, the following plants refer to Peltier and Frederich (1920, 1924) who defined susceptibility on the basis of artificial inoculation in the greenhouse (G) and/or in the field (F): Aeglopsis chevalieri (G), Atalantia ceylonica (G), Atalantia citrioides (G), Atalantia disticha (G) (Lee, 1918), Chalcas exotica (G), Casimiroa edulis (G, F), Chaetospermum glutinosum (G, F), Clausena lansium (G), Citropsis schweinfurthii (G), Eremocitrus glauca (G, F), Evodia latifolia (G), Evodia ridleyei (G), Feronia limonia [ Limonia acidissima ] (G), Feroniella lucida (G, F), Feroniella crassifolia (G), Fortunella hindsii (G, F), Fortunella japonica (G, F), Fortunella margarita (G, F), Hesperethusa crenulata (G, F), Lansium domesticum (G), Melicope triphylla (G), Microcitrus australasica (G, F), Microcitrus australasica var. sanguinea (G, F), Microcitrus australis (G, F), Microcitrus garrowayi (G, F), Paramignya monophylla (G), Paramignya longipedunculata (G) (Lee, 1918), Poncirus trifoliata (G, F), Xanthoxylum clava-herculis [ Zanthoxylum clava-herculis ] (G, F), Xanthoxylum fagara [ Zanthoxylum fagara ] (G, F) (Jehle, 1917). Atalantia ceylanica, A. monophylla, Microcitrus australis, Feronia limonia and Severinia buxifolia are immune (Reddy, 1997). In India, goat weed (Ageratum conyzoides) is reported to be a host (Pabitra et al., 1997) but confirmation is needed.
The following plants have also been reported as susceptible to X. citri, however, the original descriptions were either not confirmed (U) or contradict those of other authors (C): Aegle malmelos (C), Balsamocitrus paniculata (U), Feroniella obligata (U), Matthiola incana var. annua (U) and Toddalia asiatica (C).
Of the primary hosts listed, yuzu is highly resistant (Goto, 1992) and calamondins, Cleopatra mandarin and Sunki mandarin are immune (Reddy, 1997). Both Fortunella japonica and F. margarita are highly resistant (Goto, 1992).


Source: cabi.org
Description

A. citrulli is Gram-negative, obligately aerobic, and motile with a single polar flagellum (Willems et al., 1992). Cells are straight to slightly curved rods that are 0.2 to 0.8 by 1.0 to 5.0 um. On nutrient agar, colonies are round with slightly scalloped or spreading margins. Colonies are convex, smooth to slightly granular, and beige to faintly yellow with a translucent marginal zone. Colonies are non-fluorescent on King's medium B.

Symptons


Initial symptoms of A. citrulli in watermelon seedlings appear as water-soaked areas on the underside of cotyledons and leaves (Webb and Goth, 1965). In young seedlings, lesions can develop in the hypocotyl resulting in collapse and death of the emerging plant. As cotyledons expand, water-soaked lesions turn dark brown and often extend along the length of the midrib. Leaf lesions are light brown to reddish-brown and frequently spread along the midrib of the leaf (Latin and Hopkins, 1995). As the growing season progresses, leaf symptoms may become sparse and inconspicuous.
The characteristic symptom of bacterial fruit blotch in watermelon is a dark, olive-green blotch on the upper surface of infected fruit that begins as a small, water-soaked area a few millimetres in diameter and rapidly enlarges to a lesion several centimetres in diameter with irregular margins (Somodi et al., 1991). In a few days, the lesions may expand to cover the entire upper surface of the fruit, leaving only the groundspot symptomless. Initially, the lesions do not extend into the flesh of the watermelon. In advanced stages of lesion development, the initial infection site may become necrotic. Cracks in the rind surface may occur, resulting in fruit rot. Rotting watermelon fruit often ooze a sticky, clear, amber substance or an effervescent exudate (Latin and Hopkins, 1995).
Seedling and leaf symptoms on other cucurbits are similar to those on watermelon. Symptoms on muskmelon fruit consist of water-soaked pits on the fruit surface (Latin and Hopkins, 1995). In honeydew fruit, lesions begin as water soaked spots that, with age, become brown and cracked in the centre with a water-soaked margin. The lesions in honeydew are usually 3-10 mm in diameter.

Hosts


Symptoms can be produced in all cucurbits tested by inoculation, especially in the seedling stage (Schaad et al., 1978;Latin and Hopkins, 1995). Watermelon, cantaloupe and honeydew melons appear the most susceptible, with both foliar symptoms and blotch symptoms on the fruit (Isakeit et al., 1997). Symptoms develop on inoculated foliage of squash, cucumbers and other cucurbits, but fruit symptoms have not been observed on these hosts. Citron (Citrullus lanatus var. citroides), a common weed in parts of the southern USA, is also a host for A. citrulli. Symptoms are produced on the foliage and fruit, and seed transmission occurs in this cucurbit weed, giving it the potential to serve as an alternate host to perpetuate the bacterium.
In host range studies, symptoms were produced on tomato, eggplant and pepper foliage, but not on fruit.


Source: cabi.org
Description


Cells of E. amylovora are Gram negative rods, 0.3 x 1-3 µm in size, occur singly, in pairs and sometimes in short chains, and are motile by two to seven peritrichous flagella per cell (see Paulin, 2000, for review).
E. amylovora forms colonies of characteristic colour and colony formation on most culture media (Bereswill et al., 1998). Colonies are domed, circular, mucoid on sucrose nutrient agar (Billing et al., 1961);red to orange on MS medium (Miller and Schroth, 1972);white, circular, mucoid on KB medium (Paulin and Samson, 1973);smooth large, pulvinate, light blue opalescent with craters on CCT medium (Ishimaru and Klos, 1984);and yellow, highly mucoid or less mucoid on MM2Cu media (Bereswill et al., 1998).

Recognition


Water-soaked flowers, spurs, or shoot tips accompanied by ooze production, followed quickly by necrosis, are early symptoms of fire blight. These symptoms can be detected in an orchard or nursery by experienced observers, but may be overlooked by the inexperienced.
A suitable period for inspection is 3-5 weeks after the blossom period. Look for necrotic leaves and branches, withered blossoms, crooked shoot tips, and ooze. Ooze is more likely to be present in the morning when air humidity is high and host water potential is positive;later in the day when the air is dry, ooze may be shiny and glassy.
Cankers may form on branches and trunks at the junction between infected and healthy bark tissues;therefore, inspections may be needed every 5-7 days throughout the summer or until no new infections are observed.
In autumn, mummified fruits and leaves hanging on dead branches is an indication of fire blight. In winter, the debris helps in locating cankers since the darker bark associated with old infection can blend in with the dormant healthy bark, particularly on older trees.

Symptons


Fire blight's basic symptom is necrosis or death of tissues. Droplets of ooze on infected tissues are also an important symptom;they are the visible indication of the presence of fire blight bacteria. Except for minor differences, the symptoms of fire blight are basically the same on all host plants.
Infected blossoms initially become water-soaked and of a darker green as the bacteria invade new tissues. Within 5-30 plus days (commonly 5-10 days), the spurs begin to collapse, turning brown to black. Initial symptoms are often coincident with the accumulation of about 57 degree days, base 12.7°C, from the infection date (Steiner, 2000).
Infected shoots turn brown to black from the tip;shoots often bend near the tip to form a so-called 'shepherd-crook' shape. Shoots invaded from their base exhibit necrosis of basal leaves and the stem. Leaves and fruits may be invaded through petioles or stems or infected through wounds, resulting in discoloration followed by collapse of the leaves and fruit. During wet, humid weather, infected leaves and particularly the fruit often exude a milky, sticky liquid, or ooze containing bacteria.
From infected flowers and shoots, the bacteria may invade progressively larger branches, the trunk and even the rootstock. Infected bark on branches, scaffold limbs, trunk and rootstock turns darker than normal. When the outer bark is peeled away, the inner tissues are water-soaked often with reddish streaks when first invaded;later the tissues are dark brown to black. As disease progression slows, lesions become sunken and sometimes cracked at the margins, forming a canker.
Trees with rootstock blight may exhibit liquid bleeding from the crown at or just below the graft union in early summer. Water-soaked, reddish and necrotic tissues are visible when the outer bark is removed. Trees with infected rootstocks often exhibit yellow to red foliage about a month before normal autumn coloration. Rootstocks such as M.26, M.9 and relatives of M.9 often show these symptoms without evidence of infection in the trunk of the scion. Infection of M.7 and a few other rootstocks occurs following infection of suckers arising from the rootstocks;the infected suckers exhibit typical shoot blight symptoms. Many trees with rootstock blight will die in the first year after infection;the remaining rootstock-infected trees often die within 2-3 years.
Any plant tissues invaded by the bacteria can show ooze production on their surface. This exudate is a specific symptom of fire blight. Depending on weather conditions and on the time of the day, ooze may or may not be produced. It is most frequently observed early in the morning when the host water potential is positive. It may appear in different ways: droplets, threads or film on the plant's surface.

Impact


The long distance spread of fire blight is a rare event which in most cases seems to be the result of plants or plant tissues being moved across the oceans. Short distance spread is the result of the characteristics of the pathogen, especially its ability to produce an exudate (bacteria embedded in exopolysaccharides) which is easily transported by wind, rain, insects or birds. This is very efficient;once the pathogen has moved into a new territory it almost always colonizes and becomes established. This is accompanied by economic losses in regions where apple, pear or loquat are grown commercially;it might prevent the survival of local cultivars and could disrupt international trade. To date fire blight has colonized most of North America, Western Europe and most of the countries around the Mediterranean Sea as well as New Zealand. Outbreaks of fire blight are irregular and difficult to control.

Hosts

E. amylovora is a pathogen of plants in the family Rosaceae;most of the natural hosts are in the subfamily Maloideae (formerly Pomoideae), a few belong in the subfamilies Rosoideae and Amygdaloideae (Momol and Aldwinckle, 2000). Genera in the subfamily Spiraeoideae have been reported as hosts on the basis of artificial inoculation (van der Zwet and Keil, 1979).
Strains of E. amylovora isolated from one host are pathogenic on most other hosts. This was the case for strains isolated from natural infections on Prunus salicina in the USA (Mohan and Thomson, 1996) and on Prunus domestica and Rosa rugosa in southern Germany (Vanneste et al., 2002a). Rubus strains (see Taxonomy and Nomenclature) are host specific;they are pathogenic on brambles but not on apple and pear (Starr et al., 1951;Braun and Hildebrand, 2005). Also, a few Maloideae strains exhibit differential virulence on apple;for example, strain Ea273 was not pathogenic across the same range of apple cultivars and rootstocks as common strain E4001A (Norelli et al., 1984, 1986).
Within each group of susceptible host plants, species or cultivars may be found with a high level of resistance;such plants may show no, or limited, symptoms under natural conditions or even following artificial inoculation (Forsline and Aldwinckle, 2002;Luby et al., 2002). Lists of resistant cultivars are published for important crops (van der Zwet and Keil, 1979;Zeller, 1989;Thomas and Jones, 1992;Berger and Zeller, 1994;van der Zwet and Bell, 1995;Bellenot-Kapusta et al., 2002).
Wild Pyrus (P. amygdaliformis, P. syriaca) in southern Europe and in the Mediterranean area, Crataegus (C. oxyacantha [ C. laevigata ], C. monogyna) in northern and central Europe, and ornamentals (Pyracantha, Cotoneaster, Sorbus) throughout Europe are important sources of inoculum for apple and pear orchards.


Source: cabi.org
Description

H. flavescens is a c oarse perennial herb with thick fleshy rhizomes and erect, leafy p seudostems of 1-3 m in height. The leaves are sessile and have slightly pubescent sheaths. The ligule is 3-5 cm long and membranous. Leaf blades are elliptic-lanceolate or lanceolate, 20-50 cm long and 4-10 cm wide and abaxially (beneath) pubescent with attenuate base, membranous margins and a caudate-acuminate apex. Inflorescences are oblong spikes, 15-20 cm long and 3-6 cm wide;bracts are imbricate, oblong to ovate, 3-4.5 cm long and 2-4 cm wide, concave, 4- or 5-flowered. The bracteoles are tubular and membranous. Flowers are creamy-white to pale yellow or yellow-white in a cone like inflorescence, fragrant with yellow stamens. The calyx is 3.5-4 cm long, pubescent, approximately half the length of the corolla tube and almost as long as the bract. It is split on 1 side, apical margin entire. Corolla tube is 7-8.5 cm, long and slender. The lobes are linear, 3-3.5 cm long. The lateral staminodes are wider than the corolla lobes. The labellum is erect, creamy yellow with an orange patch at base, obcordate, longer than wide, and apex is 2-lobed. Filament is white to cream, subequaling labellum. Top of anther protruding slightly beyond lip. Ovary hairy. Stigma funnelform, margin bearded. Fruits are globose capsules 1-2 cm in diameter with three valves, containing numerous seeds but not seen in much of its invasive range.

Impact

A native of the Himalayas, H. flavescens has been introduced to many locations around the world as an ornamental and subsequently escaped cultivation to become a weed of significant economic importance in countries with favourable moist and warm climates. It threatens native forests in New Zealand, in La Réunion it outcompetes native plants and forms dense stands in wet areas such as ravine sides, roadsides, native forest margins and disturbed forests, and in Hawaii it tends to be confined to forest edges but also impacts negatively on the ecosystem. Its spread and dispersal is facilitated by vegetative regeneration of its dense rhizomes, which allows it to cover large areas of land and prevent the re-growth and establishment of native species, endangering rare and specialized plant communities. It is similar in its ecology and impacts to other invasive Hedychium spp., e.g. Hedychium coronarium and Hedychium gardnerianum.

Hosts

H. flavescens is not a weed of crops. It is an invasive species that threatens the environment, native communities and biodiversity.
Biology and Ecology
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Genetics
The chromosome number is reported to be 2 n=34.
Physiology and Phenology
H. flavescens, like its close relative, H. flavum, possesses large yellow inflorescences but can be distinguished from the latter by its hairier leaves and generally paler yellow flowers. The Zingiberoideae have a forced dormancy period during which all the above ground parts are shed and the plant overwinters as a thick, fleshy rhizome. Either just before or at the earliest signs of the wet season, individuals break dormancy with vegetative or reproductive shoots. Reproductive Biology
Spread in its invasive range is mainly by vegetative growth via rhizomes;however, in Hawaii some evidence exists that H. flavescens may be naturalizing by seed, though no fertile fruits have yet been found. Environmental Requirements
H. flavescens is a plant of the humid tropics, though being native to high altitudes, it can also tolerate cooler temperatures if in fully humid climates. It prefers areas with a mean annual rainfall of 1000-5000 mm, a mean annual temperature of 11-20ºC, and it can also tolerate frosts, though they may kill above-ground plant parts. H. flavescens requires medium to high soil fertility, and prefers to grow in open, light-filled environments which are warm and moist but will readily colonise semi and full shade under forest canopies. Altitude range in its native India is 1200-2000 m (Hooker, 1897;Mitra, 1958), 500-800 m in Sichuan, south-western China, below 2000 m Sri Lanka, and below 400 m in Hawaii but up to 2300 m where annual rainfall exceeds 1500 mm.
Climate
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Climate|Status|Description|Remark
Af - Tropical rainforest climate| Preferred
60mm precipitation per month
Am - Tropical monsoon climate| Preferred
Tropical monsoon climate (60mm precipitation driest month but (100 - [total annual precipitation(mm}/25]))
Cf - Warm temperate climate, wet all year| Preferred
Warm average temp. 10°C, Cold average temp. 0°C, wet all year
Air Temperature
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Parameter
Lower limit
Upper limit
Absolute minimum temperature (ºC)
0
-5
Mean annual temperature (ºC)
20
11
Mean maximum temperature of hottest month (ºC)
17
14
Mean minimum temperature of coldest month (ºC)
13
10
Rainfall
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Parameter|Lower limit|Upper limit|Description
Dry season duration|0|1|number of consecutive months with 40 mm rainfall
Mean annual rainfall|5000|1000|mm;lower/upper limits
Rainfall Regime
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Summer
Soil Tolerances
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Soil drainage
impeded
seasonally waterlogged
Soil texture
heavy
medium
Natural enemies
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Natural enemy|Type|Life stages|Specificity|References|Biological control in|Biological control on
Hypochniciellum ovoideum| Pathogen
not specific
Notes on Natural Enemies
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Due to its economic importance, the wide range of pests and diseases attacking cultivated ginger have been well researched. By contrast however, not much is known about the mycobiota and entomofauna of wild ginger species. Very few fungal pathogens had been reported on H. flavescens in its invasive range (Farr et al., 2008) although a strain of the soil-borne bacterium, Ralstonia solanacearum was isolated from Zingiber officinale (edible ginger) in Hawaii and caused no bacterial wilt in H. flavescens despite causing symptoms in H. gardnerianum and H. coronarium (Anderson and Gardner, 1999). The basidiomycete Leptosporomyces ovoideus was also recorded from H. flavescens in Hawaii (Farr et al., 2008).
Biological control options were subsequently investigated in New Zealand (Winks et al., 2007) following on from the research carried out in Hawaii. A survey of fungi, bacteria and invertebrates associated with H. flavescens (and H. gardnerianum) in New Zealand was carried out in 2006-07 for a national collective of regional councils and the Department of Conservation but no specialist agents were found. Furthermore, no isolates of R. solanacearum were found during the course of the surveys, even though it is recorded as present in New Zealand on other hosts, and it was concluded that the strain known to attack gingers was not established in New Zealand. Given the lack of specialist agents in New Zealand, recommendations were made that a classical control programme should be made, involving surveys in the native range of the wild ginger species of concern. A scoping survey to the Eastern Indian foothills of the Himalayas was carried out in 2008 by CABI scientists, sponsored by a consortium from Hawaii and New Zealand, and highlighted a large suite of damaging natural enemies associated with the Hedychium complex. Subsequent phases of the project have continued to consolidate and prioritise natural enemies for specificity studies, with the focus of the research being on H. gardnerianum, the most pernicious of the invasive complex.
A shoot borer (Conogethes puctiferalis) and a leaf roller (Udaspes folus) have been recorded from Hedychium sp. in India and several species of pathogens have been documented from Hedychium species including the basidiomycete, Lecanocybe lateralis Desjardin & E. Horak, from senescent leaves of H. flavescens (Indonesia) (Soares and Barreto, 2008) and Leptosporomyces ovoideus from H. flavescens in Hawaii (Gilbertson et al., 2002).


Source: cabi.org
Description

X. fastidiosa is a fastidious Gram-negative, xylem-limited bacterium, rod-shaped with rippled cell walls. It is strictly aerobic (microaerophilic), non-flagellate, does not form spores and measures 0.1-0.5 x 1-5 µm. The peach strain was given by Nyland et al. (1973) as 0.35 x 2.3 µm. See also Bradbury (1991). Thread-like strands (fimbriae) attached to the polar ends of bacterial cells can be observed in electron microscopy (Mircetich et al., 1976) and scanning electron microscopy (Feil et al., 2003b). These probably function in bacterial attachment and 'twitching' movement (Meng et al., 2005).

Recognition


Symptoms are not reliable for detection of infected plants in transit.
X. fastidiosa can be detected microscopically (light or electron) in vessels in cross-sections of petioles (French et al., 1977) or by examining xylem sap squeezed from symptomatic stems or petioles or flushed from stems or petioles onto microscope slides (De Lima et al., 1998). Flushing of xylem sap from shoots with a pressure chamber allows the testing of larger sample sizes and avoids inhibitors for PCR (Bextine and Miller, 2004). Methods such as grafting to susceptible indicator plants or vector tests (Hutchins et al., 1953) are still available, and may have their place in certification schemes in which woody indicators are routinely used. X. fastidiosa can also be isolated onto suitable selective media (Davis et al., 1978, 1983;Raju et al., 1982;Wells et al., 1983). The identity of cultured bacteria can be confirmed by SDS-PAGE (Bazzi et al., 1994). Serological methods are less sensitive (10- to 100-fold) than culture but are the easiest means of detecting and identifying the bacterium, by ELISA or use of fluorescent antibodies (French et al., 1978;Walter, 1987;Hopkins and Adlerz, 1988;Sherald and Lei, 1991). Strains differ in quantitative reaction to antisera and in ease and efficiency of culture. DNA hybridization probes and PCR primers specific to X. fastidiosa have been developed (Firrao and Bazzi, 1994;Minsavage et al., 1994). X. fastidiosa can also be detected in its insect vectors (Yonce and Chang, 1987). The characterization and identification of strains chiefly employs molecular genetic methods (e.g., Chen et al., 1992;Hendson et al., 2001;Coletta-Filho et al., 2003), and can be expected to remain indefinitely in a state of change.
Different diagnostic methods used or developed for the detection and identification of X. fastidiosa are detailed in Janse (2009). Recent advances in detection include on-site molecular detection using real-time loop-mediated isothermal amplification (Yaseen et al., 2015).

Symptons

On grapevines
The most characteristic symptom of primary infection is leaf scorch. An early sign is sudden drying of part of a green leaf, which then turns brown while adjacent tissues turn yellow or red. The desiccation spreads and the whole leaf may shrivel and drop, leaving only the petiole attached. Diseased stems often mature irregularly, with patches of brown and green tissue. In later years, infected plants develop late and produce stunted chlorotic shoots. Chronically infected plants may have small, distorted leaves with interveinal chlorosis and shoots with shortened internodes. Highly susceptible cultivars rarely survive more than 2-3 years, despite any signs of recovery early in the second growing season. Young vines succumb more quickly than do older vines. More tolerant cultivars may survive chronic infection for more than 5 years (Hewitt et al., 1942;Goodwin and Purcell, 1992).
On peaches
Young shoots are stunted and bear greener, denser foliage (due to shorter internodes) than healthy trees. Lateral branches grow horizontally or droop, so that the tree seems uniform, compact and rounded. Leaves and flowers appear early, and leaves remain on the tree longer than on healthy trees. Affected trees yield increasingly fewer and smaller fruits until, after 3-5 years, they become economically worthless (Hutchins, 1933).
On citrus
Trees can start showing the symptoms of variegated chlorosis from nursery size up to more than 10 years of age. Younger trees (1-3 years) become systemically colonized by X. fastidiosa much faster than do older trees. Trees more than 8-10 years old are not usually totally affected, but rather have symptoms on the extremities of branches. Affected trees show foliar chlorosis resembling zinc deficiency with interveinal chlorosis. The chlorosis appears on young leaves as they mature and may also occur on older leaves. Newly affected trees show sectoring of symptoms, whereas trees which have been affected for a period of time show the variegated chlorosis throughout the canopy. As the leaves mature, small, light-brown, slightly raised gummy lesions (becoming dark-brown or even necrotic) appear on the underside, directly opposite the yellow chlorotic areas on the upper side.
Fruit size is greatly reduced;it may take 550 affected fruits to fill a field box, compared with 250 normal fruits. The sugar content of affected fruit is higher than in non-affected fruit, and the fruit has a hard rind, causing damage to juicing machines. Blossom and fruit set occur at the same time on healthy and affected trees, but normal fruit thinning does not occur on affected trees and the fruits remain small but open earlier. Since more fruits remain, total production is not greatly reduced. On affected trees of cv. Pera and other orange cultivars, fruits often occur in clusters of 4-10, resembling grape clusters. Affected trees show stunting and slow growth rate;twigs and branches die back and the canopy thins, but affected trees do not die (Chang et al., 1993a,b;Lee et al., 1991, 1993).
Control has been achieved by removing inoculum in established orange groves and using sanitary measures to prevent infection of nurseries and new groves. All symptomatic branches from trees older than 3 years are cut off up to 1 m below the most basal symptoms. Symptomatic trees less than 4 years old are removed. To prevent the infection of nursery trees, nurseries are located away from citrus plantings, sharpshooters are controlled prophylactically by insecticides, and buds are taken from trees tested free of X. fastidiosa and grown vectors in screen houses or glass houses to exclude vectors. The effectiveness of these measures (Rodas, 1994) indicates that most spread of variegated chlorosis is from tree to tree within citrus orchards (Laranjeira, 1997).
On olives
On olives, quick decline syndrome is characterised by the development of leaf scorch symptoms and desiccation of small twigs and branches. Symptoms generally initiate in the upper part of the canopy on one or two branches, and then extend to the remainder of the crown. Severely affected plants are often pruned heavily, favouring spindly new growth which also succumbs to scorch symptoms. The tree may send out suckers from the base of the plant which subsequently die back, until the root system dies entirely (Martelli, 2016a). Grafting experiments have demonstrated that it takes at least 7 months for leaf scorch symptoms to appear on the grafted plant part (European Food Safety Authority, 2015).
Symptoms are found on all known varieties of olive. Older varieties, such as Ogliarola Salentina, Cellina di Nardò and common varieties Frantoio and Coratina, appear susceptible. It is suggested that the variety Leccino seems less susceptible, although records are based on field observations and are yet to be experimentally confirmed. Apparent variation in olive varietal susceptibility may be the result of differences in disease vector pressures in the areas where the disease is present (European Food Safety Authority, 2015).
Vectors
Vector feeding causes no visible damage. Xylem feeders are prodigious feeders, consuming hundreds of times their body volumes per day in xylem sap. Most non-xylem-feeding leafhoppers produce a sugary or particulate excrement, but that of xylem feeders is watery, drying to a fine whitish powder (brochosomes) where abundant (Rakitov, 2004). The excrement of froghopper nymphs takes the form of persistent bubbles or 'froth;that surrounds the body of the insect, presumably to provide protection from natural enemies.

Hosts

No grapevine (Vitis spp.) species are known to be immune to Pierce’s disease strains of X. fastidiosa, but American species used as rootstocks (V. aestivalis, V. berlandieri, V. candicans, V. rupestris) and hybrids derived from them are tolerant and some may be resistant, as is V. rotundifolia (Goheen and Hopkins, 1988). Almonds and lucerne can be hosts of the grapevine strains, but the diseases caused by X. fastidiosa in these three crop species are independent within California, USA, suggesting as yet unidentified biological differences (Purcell, 1980b). A very high percentage (75% of those tested) of crop, wild plant and weed species can carry Pierce’s disease strains of the bacterium without symptoms (e.g. wild grasses, sedges, lilies, various bushes and trees) (Raju et al., 1983;Hopkins and Adlerz, 1988;Hill and Purcell, 1995b). It is likely that in most symptomless host species, X. fastidiosa multiplies to lower populations and moves systemically less often than in pathological hosts. For example, blackberry (Rubus spp.) can be a systemic host, but the bacterium multiplies in mugwort (Artemisia douglasiana) without systemic movement (Hill and Purcell, 1995b). Hosts can be classified as propagative or non-propagative, systemic or non-systemic, and symptomatic or non-symptomatic (Purcell and Saunders, 1999b). Propagative, systemic hosts are the best hosts for efficient vector acquisition of bacteria, but vectors can acquire the bacterium from non-systemic hosts. Acquisition efficiency is proportional to the populations of live bacterial cells within plant tissues (Hill and Purcell, 1997).
Peach (Prunus persica) strains of X. fastidiosa cause peach phony disease (Wells et al., 1983), which also attacks Prunus salicina (causing leaf scald). All cultivars, forms and hybrids of peach are attacked, whether on their own roots or other rootstocks. Plums (Prunus domestica), almonds (P. dulcis), apricots (P. armeniaca) and the wild P. angustifolia were reported susceptible to phony disease before the association with X. fastidiosa was established. This reported range partly overlaps that of the grapevine-infecting strains. Various perennial weeds of orchards, such as Sorghum halepense, may act as reservoirs for the peach-infecting strain (Yonce, 1983;Yonce and Chang, 1987), but the plant host range of Prunus strains from the south-eastern USA has not been investigated extensively. Pierce's disease strains also cause almond leaf scorch disease (Davis et al., 1980), but the almond strains infect grape in low populations and without causing disease (Almeida and Purcell, 2003).
X. fastidiosa in the wide sense also causes leaf scorch in Acer rubrum (Sherald et al., 1987), Morus rubra (Kostka et al., 1986), Platanus occidentalis (Sherald, 1993a,b) (wilt and leaf scorch), Quercus rubra (Chang and Walker, 1988), Ulmus americana and Vinca minor (stunt). Strains from Ulmus and from P. occidentalis are not reciprocally infectious (Sherald, 1993a). The bacteria involved are not known to be transmissible to grapevine. Diseases of numerous woody ornamental plants in southern California, USA, including olive, date palm and rosemary, have been associated with X. fastidiosa but a causal relationship is still unproven (Wong and Cooksey, 2004). Until their relationships and pest significance have been clarified, they can all be regarded as potentially dangerous for Europe and the Mediterranean region.
X. fastidiosa causes citrus variegated chlorosis in Brazil (Lee et al., 1991;Chang et al., 1993;Hartung et al., 1994) and Argentina (Brlanksy et al., 1993). The disease affects mostly sweet oranges (Citrus sinensis);it has been observed especially on cultivars Pera, Hamlin, Natal and Valencia. It occurs on trees propagated on all commonly used rootstocks in Brazil: C. limonia, C. reshni and C. volkameriana. The disease has not been observed on C. latifolia or mandarins (C. reticulata), even when the trees were planted in severely affected orange groves (Li et al., 2000). The effectiveness of removing diseased citrus trees to prevent further spread of variegated chlorosis in citrus (Rodas, 1994) strongly suggests that most spread of this disease is from tree to tree within the crop. Control measures require the production of disease-free nursery trees in protected environments.
Citrus blight in Florida, USA, has been associated with X. fastidiosa (Adlerz et al., 1989;Hopkins et al., 1996);however the preponderance of evidence suggests that it is not the cause of blight (Derrick and Timmer, 2000).
Plum leaf scald is an important crop-limiting disease caused by X. fastidiosa from Brazil through Argentina. The South American plum leaf scald strains appear to differ from those in North America, as there are no reports of phony disease of peach in South America. The plum leaf scald strains in Brazil may have wide plant host ranges (Leite et al., 1997). A leaf scorching disease of coffee (De Lima et al., 1998) is caused by strains of X. fastidiosa that appear to be closely related to the citrus variegated chlorosis strains (Rosato et al., 1998), but its ability to cause disease in citrus (Li et al., 2001) is controversial.
In Europe and the Mediterranean region, grapevine and citrus are clearly the most significant potential crop hosts, although peach and plum are also important. Strains that cause leaf scorch diseases in oak, elm, sycamore (plane) (Hearon et al., 1980), mulberry (Kostka et al., 1986) and other tree species are also potentially damaging. Many other hosts could carry the bacterium, without necessarily being significantly affected.
X. fastidiosa has been implicated as the causal agent of olive quick decline syndrome in Europe. In 2013, X. fastidiosa subsp. pauca was associated with quick decline syndrome on olive, almond and oleander in Europe (southern Italy, Apulia region) (European Food Safety Authority, 2015). Symptomatic olive trees were often affected by multiple pests, including X. fastidiosa, several fungal species, and Zeuzera pyrina (leopard moth) (Nigro et al., 2013). Recent experimental evidence (Saponari et al., 2016) has confirmed X. fastidiosa as the causal agent of olive quick decline syndrome in Italy (European Food Safety Authority, 2016). In the USA a study evaluating olive as a host for X. fastidiosa concluded that subsp. multiplex was present but was not the cause of the leaf scorch and dieback symptoms observed on olive trees in California (Krugner et al., 2014). However, X. fastidiosa subsp. pauca has been implicated as a causal agent of olive plant dieback and leaf desiccation in Argentina (Haelterman et al., 2015). More recently, leaf scorch symptoms on olive trees in Brazil have been associated with X. fastidiosa subsp. pauca (Coletta-Filho et al., 2016).
The host range of X. fastidiosa based on the available peer-reviewed literature is presented in European Food Safety Authority (2015).
According to the European Food Safety Authority (2016), the current list of host plant species for X. fastidiosa consists of 359 plant species (including hybrids) from 204 genera and 75 different botanical families.


Source: cabi.org
Description

Sporangia are hyaline, ellipsoid or elongated-ovoid (length x width = 25-97 x 14-34 µm, mean 46-65 x 21-28 µm), sympodial, semipapillate, and deciduous, carried on a short stalk. They are produced readily on most media if plant material is included. They are also produced on V8 agar plates, although not consistently. Chlamydospores are large, round, hyaline or yellow-cinnamon depending on substrate. They can be terminal and intercalary or more rarely lateral, and are a good diagnostic feature, especially because of their size (20-91 µm, mean 46-60 µm). P. ramorum is a heterothallic, amphigynous species, and both mating types are known in nature but do not readily form sexual spores when artificially crossed. Measurements of mature gametangia are as follows: oogonial diameter, mean 30.5 µm, range 25-35 µm, oospore diameter, mean 25.5 µm, range 22.5-27.5 µm, antheridial width, mean 17.3 µm, antheridial length, mean 15.0 µm. Growth is optimal at 18-20¡C: a relatively slow grower. Hyphae are often extremely knobbly, although they lack swellings, and abundant septation can be observed, especially when producing chlamydospores. Mycelium is appressed, forming concentric growth rings more or less pronounced based on the type of media (Werres et al., 2001).

Symptons

P. ramorum causes three distinct types of disease with corresponding symptoms.;Stem Cankers (Rizzo et al., 2002a).;The cankers resemble those caused by other Phytophthora species. Discoloration can be seen in the inner bark, the cambium and within the first few sapwood rings. Discoloration is always associated with the cankers, but its intensity is extremely variable, ranging from dark-brown, almost black, lesions to slight discoloration of the infected tree tissue. Black zone lines are often, but not always, present at the edge of the cankers. Smaller tanoaks (Notholithocarpus densiflorus) tend not to have any zone lines. Most notably, P. ramorum cankers stop abruptly at the soil line, and there are few reports of root infection in tanoak. Viburnum is the only host in which root collar infection is common (Werres et al., 2001). Typical bleeding symptoms can be seen on the outside of the cankers. Bleeding is not necessarily associated with cracks or wounds, and tends to be rather viscous in consistency. A distinct fermentation smell (or alcoholic smell) emanates from bark seeps. Intensity and viscosity of bleeding changes with time. Older cankers may display a thin, brown-amber crust where seeps were originally present. Crown symptoms are often associated with expansion rate of cankers. Rapidly expanding cankers rapidly girdle the tree. In this case, there is no real crown decline, but once the tree has exhausted the resources accumulated in its aerial part, the whole crown browns. The entire foliage turns orange-brown and then becomes grey with time. The name 'sudden oak death' was coined because of the high frequency of rapidly declining trees. In the phase between girdling and apparent death of the crown, secondary processes are initiated. These include growth and fruiting of Annulohypoxylon thouarsianum, syn. Hypoxylon thouarsianum. A. thouarsianum will cause a mottled decay of portions of the sapwood and will fruit abundantly on the bark. Other secondary processes include attacks by bark and ambrosia beetles and acceleration of decay processes, at times with basidiocarps produced on trees which are still green.;When cankers are slow-growing, typical decline symptoms can be seen in the crown and include: chlorosis of the foliage, premature leaf abscission resulting in sparse crowns, and sometimes dieback of branches corresponding to portions of the stem affected by the canker. Epicormic shoots are often associated with both types of cankers (slow and fast). On oak species, most cankers are found within 1 m of the root collar, but cankers higher up on the stem and on major branches are not uncommon. Oak leaves, twigs, and juvenile plants are rarely infected. Tanoak cankers tend to be present throughout the vertical length of the tree and most trees have multiple cankers on them. Plants of all ages can be infected and killed. Leaves and twigs can also be infected. Foliar infection can precede or follow twig infection and it results in leaf spotting and a characteristic blackening of the main rib of the leaf, with lesions continuing into the petiole.;Leaf Blight and Branch Dieback (Rizzo et al., 2002b, Garbelotto et al., 2003).;Leaves develop lesions often associated with twig dieback. The primary infection court can be either in the twig or in the leaf. Cankers develop on branches. Symptoms on leaves develop rather rapidly and may result in death of the leaf. Rhododendron spp., Pieris spp. and Rhamnus spp. display these symptoms. In ericaceous hosts with small leaves (e.g. Vaccinium ovatum and Arctostaphylos spp.), foliar symptoms are not as pronounced. Leaf abscission and cane cankers are more common, resulting in the death of clumps of branches. Symptoms on coniferous hosts such as Douglas fir (Pseudotsuga menziesii) and Grand fir (Abies grandis) fall into this general category. In these two hosts, branch tips are typically affected. Branch tips, especially the last year's growth, are girdled and will wilt. Needles hang from the infected branch at first and then will drop, leaving a barren branch tip appearing similar to browse injury.;Leaf Spots, Blotches, and Scorches (Rizzo et al., 2002b, Garbelotto et al., 2003).;In some hosts, the disease affects leaves but not the twigs or branches. Lesions are normally associated with the accumulation of water on the leaf. These symptoms are in general rather nondescript. Lesions on Umbellularia californica are generally dark in colour, often at the leaf tip where water accumulates. Lesions are generally demarcated by an irregular margin, often followed by a chlorotic halo. Premature chlorosis of the entire leaf, followed by its abscission, is common in drier areas. Infection in Aesculus californica starts as light circular spots, coalescing into large blotches often affecting the whole leaf, and at times the petiole. In Acer macrophyllum, symptoms appear as a marginal leaf scorch. The scorch does not, at least initially, affect the whole leaf contour, and scorched portions are interrupted by healthy areas.

Hosts

Quercus rubra, Q. palustris, Pittosporum undulatum and many other species are regarded as potential hosts: for these species, inoculation experiments have been completed, confirming susceptibility, but no natural infection has been recorded to date (2003). A database of species tested for susceptibility is available at the Risk Analysis for Phytophthora ramorum website (http://rapra.csl.gov.uk/). More information on host range is given in the following references: Werres et al. (2001);Davidson et al. (2002a);Hansen and Sutton (2002);Linderman et al. (2002);Maloney et al. (2002);Parke et al. (2002);Rizzo et al. (2002a, b);Tooley and Englander (2002);Garbelotto et al. (2003);Huberli et al. (2003) and Kliejunas (2010). A host list is maintained by the USDA Animal and Plant Health Inspection Service (http://www.aphis.usda.gov/plant_health/plant_pest_info/pram/downloads/pd...). To date (2012) there are over 120 species listed. The California Oak Mortality Task Force (www.suddenoakdeath.org) also maintains a host list with photos of symptoms.


Source: cabi.org
Description

C. abieitis is an autoecious microcyclic rust, producing the telial stage on the needles of species of Picea.

Recognition

Yellow transverse bands appear in the current year’s new needles. Linear orange-brown telia are produced in those bands on the undersides of the needles in late summer or autumn, and persist through the winter (Wilson and Henderson, 1966;Smith et al., 1988).

Symptons

Infections only occur on the current year’s needles. Light-yellow spots appear at points of infection, usually merging to form deep yellow transverse bands across the leaf. If infection is extensive, trees or entire stands may appear yellow rather than green. Most of the infected needles are dropped the following spring, after telia have matured and sporulated (Murray, 1955;Wilson and Henderson, 1966;Mordue and Gibson, 1978).

Impact

C. abietis is a microcyclic rust fungus;an obligate parasite completing its life cycle on species of Picea (spruce). Only the current year’s needles of Picea are infected and those needles are shed early. Reported from northern Europe and Asia, the fungus is a Regulated Pest for the USA. It is absent from North America, where susceptible species are native, and Australia and New Zealand, where they are introduced. Although usually not a significant problem in its native range, because conditions are not favourable for heavy infections every year (Smith et al., 1988;Hansen, 1997), this rust could be more damaging as an invasive in other temperate areas. Due to the fact that small amounts of infection may be overlooked, accidental introduction could occur through importation of infected seedlings or young trees.


Source: cabi.org
Description


A shrub or small tree, generally up to 2.5-4 m (max. 6) high. Stem round, usually simple (rarely branched), pale green, thickly covered with hoary pubescence which readily rubs off. Leaves decussate, obovate, acuminate 10-20 cm long and 4-10 cm wide. Inflorescence a dense, multiflowered, umbellate cyme arising from the nodes and appearing axillary or terminal. Corolla slightly campanulate, with 5 sepals that are 4-5 mm long;segments ovate, acute, rather concave, dull purple bordered with white on the upper side, silvery on the underside. Fruits sub-globose, ellipsoid or ovoid, recurved follicle, 7.5-10.0 cm. Seed light-brown, broadly ovate, flattened, 3.2 cm with silky hairs. A white milky sap is exuded from any wound on the plant.

Hosts

C. procera is a serious weed in pastures, overgrazed rangelands and poorly managed hay fields.


Source: cabi.org
Description

An erect, branched (occasionally unbranched) annual herb, green, more or less coated with white mealy pubescence. Cotyledons petiole, lanceolate-linear, mealy, bluish-grey with a reddish tinge beneath, 6–12 mm long and 1.5–4 mm broad (Korsmo et al., 1981). Roots stout and tapering at the end. Many branches may emerge from main tap root system. Epidermal cells are more or less polygonal in shape. Fewer, smaller stomata on upper compared to lower leaf surface (Srivastava, 1967). Stems erect, branched towards apex, 0.2–2 m tall, glabrous, furrowed, often with red or light-green streaks, branching varies from slight to extensive. Leaves alternate, simple ovate to rhomboid-oval, uppermost leaves mostly lanceolate, sometimes linear and sessile, glabrous, usually white with a mealy-covering, particularly on young leaves, all leaves densely covered with small, utriculate hairs. Inflorescence in irregular spikes clustered in panicles at the ends of the branches. Flower perfect, small, sessile, green;calyx of 5 sepals that are more or less keeled and nearly covering the mature fruit;petals 1;stamens 5, pistil 1, with 2 or 3 styles, ovary single-celled, attached at right angles to the flower axis. Fruits is an achene (seed covered by the thin papery pericarp). Seed nearly circular in outline, oval in cross section, sides convex, glossy, black, mean size 1.5 mm x 1.4 mm in diameter, weight 1.2 mg.

Impact

C. album seems to grow most vigorously in temperate and subtemperate regions, but it is also a potentially serious weed in almost all winter-sown crops of the tropics and subtropics. It is a common weed in about 40 crops in 47 countries, being most frequent in sugarbeet, potatoes, maize and cereals. It is one of the principal weeds of Canada and Europe, and in India, Mexico, New Zealand, Pakistan and South Africa is ranked amongst the six most serious weeds. In temperate climates, it is a problem in almost all summer- and winter-sown crops.

Hosts

C. album seems to grow most vigorously in temperate and subtemperate regions, however it is also a potentially serious weed in almost all winter-sown crops of the tropics and subtropics. It is a common weed in about 40 crops in 47 countries, being most frequent in sugarbeet, potatoes, corn and cereals. It is one of the principal weeds of Canada and Europe, and in India, Mexico, New Zealand, Pakistan and South Africa is ranked amongst the six most serious weeds (Holm et al., 1977). In temperate climates, it is a problem in almost all summer- and winter-sown crops.
In subtropical regions it is most common in wheat, chickpea, barley, winter vegetables, horticultural gardens, maize, sunflower and soybean. In addition, it is an important weed of tea and upland rice in Japan, citrus orchards and vineyards in Spain, cotton, soyabean and strawberries in the former Soviet Union, cotton, pastures and peanuts in the USA, rice in Mexico and tobacco in Canada (Holm et al., 1977). In Europe and America, it is a problem weed in maize, soybean, wheat, barley, potato and all vegetable crops.


Source: cabi.org
Description

C. cardunculus is an erect perennial herb that can grow between 60 and 150 cm, but has been known to grow as tall as 2 m with a spread of 2 m (Weeds of Australia, 2016;Elzebroek and Wind, 2008). It has a large taproot that regenerates each year (Kelly and Pepper, 1996). The root can grow to the depth of 2 m (Parsons and Cuthbertson 2001). The stems are thick and rigid, which often branch in the upper parts, they are longitudinally ribbed and covered in a cotton down. The above-ground portion of the plant dies down each year, but off-shoots rise from the rootstock next growing season (Elzebroek and Wind, 2008).

Impact

C. cardunculus is an erect perennial herb, commonly known as cardoon or artichoke thistle. Native to southern Europe and North Africa, it has been widely introduced and is recognised as invasive in parts of Australia, the USA, Chile and Argentina. It can form dense monocultures, displacing native vegetation and degrading native plant communities. In California, it is categorized as a Most Invasive Wildland Pest Plant, category A-1, on the Californian Exotic Pest Plants of Greatest Ecological Concern. It can aggressively invade and disrupt natural habitats and has been described as a robust invasive plant that exhibits characteristics of the world’s worst weeds.

Hosts

C. cardunculus is known to be a significant agricultural pest, in particular pastoral activity (Weeds of Australia, 2016). Once established C. cardunculus can become the dominant vegetation in an area by monopolising light, moisture and nutrients from the soil. In Australia it has known to adversely affect pastures, and lucerne, by crop contamination. The prickly nature of the herb deters grazing sheep and cattle (Parsons and Cuthbertson, 2001). A thick infestation can also limit the movement of livestock (Thomsen et al., 1986).

Biological Control
<br>Biological control is not feasible as C. cardunculus has closely related cultivated species, Cynara scolymus and Cynara altilis. It is unlikely that any biological control would therefore be restricted to C. cardunculus (Thomsen et al., 1986).<br>However in the USA, the accidentally introduced artichoke fly attacks the flower head of C. cardunculus. It is not an approved biocontrol agent and does not significantly affect commercial C. scolymus crops. The fly’s affect on native thistles is still being studied, and the impact on C. cardunculus populations are not known (DiTomaso et al., 2013).

Source: cabi.org
Description

D. aegyptium is a grass, with characteristic 'bird's foot' digitate inflorescence, up to 50 cm tall.
Annual, never stoloniferous. Culms up to 50 cm tall, up to 5 noded, geniculately ascending, usually rooting from the lower nodes, thus giving the plants a pseudo-stoloniferous appearance, not rarely forming radiate mats, branched from the lower nodes;internodes cylindrical, glabrous, smooth, striate, exserted above, variable in length;nodes thickened and glabrous. Young shoots cylindrical or rounded. Leaf-sheaths keeled, up to 5 cm long, rather lax, striate, tuberculately hairy on the keel or quite glabrous;ligule membranous, about 1 mm long, ciliolate along the upper edge;leaf blades flat when mature, rolled when in bud, linear, tapering to a fine point, up to 20 cm long and 12 mm wide, with 3-5 primary nerves on either side of the midrib, glaucous, usually more or less densely tuberculately hairy along the margins and the keel, less conspicuously so on the adaxial surface towards the tip.
Inflorescence digitate, composed of 4-8 spreading spikes. Spikes 1.5-6 cm long, on maturity often somewhat recurved, greenish-yellow or pallid;rachis keeled, smooth near the base, scaberulous towards the apex, tip mucroniform and curved. Spikelets 4 mm long, strongly compressed, ovate, solitary, sessile, patent alternately left and right on the ventral side of the axis;dense, forming a very flat comb, usually 3-flowered;lower florets bisexual, the upper florets rudimentary;axis without terminal stipe. Lower glume 2 mm long and 2 mm wide, ovate in profile, 1-nerved, sharply keeled, keel scabrid;upper glume 2 mm long excluding the 1.5-2 mm-long awn, oblong in profile, 1-nerved, sharply keeled, keel scabrid. Rachilla slender. Lemmas 3-4 mm wide, the upper smaller in dimensions (but similar), folded about the keel which is scabrid, broadly ovate in profile, lateral nerves delicate and indistinct;uppermost lemma epaleate. Paleas about 3 mm long, 2-nerved, keels scabrid, dorsally concave, shortly bifid at the apex. Three anthers, pale-yellow, 0.3-0.5 mm long, anther cells somewhat remote, with a conspicuous connective. Caryopsis sub-triangular or sub-quadrate, laterally compressed, rugose, light-brown, apex truncate, never convex, remains of pericarp at times visible. (Fisher and Schweickerdt, 1941).

Recognition

D. aegyptium is usually identified initially by the characteristic 'bird's foot' arrangement of the inflorescence with 4-8 spreading spikes. It is sometimes found as seed during inspections of seed samples.

Impact

Producing large quantities of seeds, D. aegyptium is a pioneer grass that quickly colonizes disturbed areas with light sandy soils, often near to coasts or where water accumulates. It is a common component of weed floras throughout the tropics but is rarely reported as an aggressive weed on its own. It is not on federal or state noxious weed lists in the USA and is not recorded on the ISSG database but is recorded by PIER (2016) as invasive on a number of Pacific and American islands including French Polynesia Islands, Micronesia, the Northern Mariana Islands and Hawaii. It is also listed as invasive on islands in the Mediterranean, the USA, Mexico, Costa Rica, Puerto Rico, Virgin Islands and the Lesser Antilles (Vibrans, 2009;Florida Exotic Pest Plant Council, 2011;Chacón and Saborío, 2012;Burg et al., 2012;Rojas-Sandoval and Acevedo-Rodríguez, 2015;DAISIE, 2016;USDA-NRCS, 2016).

Hosts

D. aegyptium is a ubiquitous weed in many cropping systems around the world. Holm et al. (1977) classified the degree of importance of D. aegyptium on crops in different countries, in decreasing level of severity, as follows: a serious weed of cotton in Thailand;a principal weed of cotton in Australia, Kenya, Mozambique, Nigeria, Sudan, Tanzania, Uganda and USA, of sugarcane in India, the Philippines and Taiwan, of groundnuts in the Gambia and USA, of maize in Ghana and India and of rice in Sri Lanka and India;a common weed of rice in Indonesia, Nigeria and the Philippines, of coffee in Kenya and Tanzania and of tea in Taiwan and it occurs in bananas, pawpaws, cassava, citrus, sweet potatoes and millet in countries of Africa, Asia and Central America.
D. aegyptium has also been recorded in the weed flora of the following crops: aubergines in India;black gram (Vigna mungo) in Bangladesh and India;cassava in the Philippines;chickpeas in India;chillies (Capsicum) in India;cotton in Brazil, South China, India, Nepal, Thailand, USA and Zambia;cowpeas in India;finger millet (Eleusine coracana) in India;groundnuts in Bangladesh, Ghana, India, Senegal and USA;maize in India, Nigeria, Pakistan, Philippines and USA;jute in India;mint in India;mung beans (Vigna radiata) in India;okras in Nigeria;pawpaws in the Philippines;pearl millet (Pennisetum glaucum) in Burkina Faso, Mali and India;pigeon peas in India;potatoes in the Philippines;rice (transplanted) in India, Indonesia and Pakistan;rice (upland) in Cameroon, Gambia, India and Nigeria;sesame in India;sorghum in Australia, India;soyabeans in Ghana, India, Côte d'Ivoire, Pakistan, Senegal;sugarcane in India, Taiwan and Peru;sweet potatoes in the Philippines, Taiwan and USA;tobacco in India;wheat in Bangladesh and India;yams in India and the Philippines.


Source: cabi.org
Description

F. convolvulus is an annual or perennial climbing herb with a thin, spindle-formed and deep root, which is often profusely branched. The stem is slender, 5-250 cm long, with long internodes. It is freely branched from the base, smooth to slightly rough, greenish, sometimes with a reddish tinge, trailing on the ground or twining around other plants. The leaves are alternate, 2-6 cm long, long-petioled, elongate-ovate, pointed, heart- or arrow-shaped. The stipule sheath or ochrea with smooth margins. Flowers are small, inconspicuous, up to 5 mm in diameter, and grouped in short axillary clusters of 2 to 6 flowers or in terminal interrupted or spike-like racemes. The perianth is reddish green, white inside and along the margins;the short pedicels are articulate near the upper end. The fruit is a triangular achene, 3-4 mm long, with an obtuse base and pointed top, minutely pitted, brownish black, dull, after maturity enclosed by the somewhat enlarged outer perigon leaves (Korsmo, 1954;Holm et al., 1991;Conert et al., 1981).
The seedlings have long cotyledons, 7-33 mm in length. They are four times longer than wide, with obtuse points. The upper leaf surface is dull dark green;the lower leaf surface is light green, with a distinct central nerve. The expanded cotyledons generally assume a 120° angle, rather than being opposite, at the point of which the primary leaf appears. At the beginning, the primary leaf is often laterally rolled up, with a blueish or reddish green tinge (Schwär et al., 1970;Hume et al., 1983).

Impact

F. convolvulus is a weedy species of gardens, cultivated fields, open habitats, orchards, non-crop areas, waste areas, and disturbed sites. It is well-adapted to a wide range of climatic conditions and soils. This species is a prolific seed producer and has the potential to produce up to 30,000 seeds/plant. Seeds can be dispersed by farm machinery, and water. It is also a common contaminant of wheat and other cereal crops.
F. convolvulus is often a serious weed in cereals, vegetables and horticultural crops (FAO, 2015). Currently, it is listed as invasive in the Dominican Republic, Cuba, Australia, New Caledonia, and New Zealand (Webb et al., 1988;MacKee, 1994;Wilson, 2008;Acevedo-Rodriguez and Strong, 2012), but it is also ranked as a serious weed in 20 crops in more than 41 countries around the world (Holm et al., 1991).

Hosts


A list of crops in which F. convolvulus is, or could be, a problem weed includes almost every crop of the temperate zone. Worldwide, F. convolvulus is most troublesome in cereals, but it may also cause yield losses in potatoes, sugarbeet and vegetables, as well as vineyards and orchards. According to Holm et al. (1991), it is a weed of 25 crops in 41 countries and in 20 crops of these countries it is ranked as a serious weed.


Source: cabi.org
Description

The plant is a vigorous growing herbaceous perennial with annual tubular, glabrous stems that ascend from an erect base. These stems are light green often with reddish flecks, branched and reach up to 3 m in height (Beerling et al., 1994). Where introduced, F. japonica is generally taller than in its native range in Japan (Holzner and Numata, 1982), where it is recorded as being 0.3-1.5 m tall (Makino, 1997). Stems arise from strong rhizomes to form a dense thicket. Rhizomes are thick and woody when old, and have been recorded as spreading 5-7 m laterally (Pridham et al., 1966). The rhizome has ring-like structures at about 2 to 4 cm intervals which are reduced leaf scales, whilst on the underside are adventitious roots travelling into the soil. The rhizome snaps like a carrot when fresh to reveal a yellow/orange colour. The main aerial shoots emerge from the large bulbous rhizome crown about 30 cm x 30 cm across. This acts as a carbohydrate store in the winter months when it represents the complete live biomass of the plant. Spreading out from this central region are a number of radial penetrating rhizomes that twist together to form a sizeable and considerable penetrating force. The leaves are 5-12 cm x 5-8 cm, broadly ovate, cuspidate at the tip and truncate at the base. At the base of each leaf petiole is located a small gland that functions as an extra-floral nectary. The flowers are off-white and borne in ochreate clusters of 3 to 6 on terminal and axillary panicles, with the main axis up to 10 cm long and with slender branches 5-9 cm long (Lousley and Kent, 1981). Sepals 5, the outer 3-keeled;stamens 8, included within a perianth in male-sterile plants, filaments 0.4 mm, anthers small, flat, empty 0.3 mm, styles 3, distinct, stigma fimbriate, exceeding the perianth;perianth greatly enlarged in fruit and conspicuously winged, completely enclosing the trigonous achene. Achenes (or nuts) 2-4 mm long, 2 mm wide, dark brown and glossy, mean weight 1.6 mg. Inflorescences initially erect but drooping at maturity. Male fertile plants are not known from the introduced range.

Recognition


The UK Environment Agency have produced a Code of Practice, and the Cornwall and Devon Knotweed Forum have produced an excellent guide which has advice on identifying the plant in the field at various stages of the season. as have the British Columbia Ministry of Forest and Range.

Impact

F. japonica is an extremely invasive weed despite its lack of extensive sexual reproduction in most of its introduced range. It is included on various lists of invasive weeds and is one of the 100 worst invasive species as identified by the IUCN. It is a potential contaminant of soil, and its ability to tolerate a remarkable range of soil types and climates means that it has the potential to spread much further than it has to date. It has gained a fearsome reputation for breaking through hard structures in the built environment and being almost impossible to eradicate once it has taken hold and is often recognized as one of the most pernicious weeds in any recipient country.

Hosts


Amphibians have been shown to have reduced foraging success in knotweed patches (Maerz et al., 2005) and any native species forced to compete with knotweed, i.e riparian plants, are likely to suffer consequences, as demonstrated by Gerber et al. (2008).


Source: cabi.org
Description

T. domingensis is a rhizomatous perennial emergent wetland macrophyte. Ramets (culms) range from 1-6 m tall (Denny, 1985b) and consist of numerous slender, linear, distichous leaves with a sheathing base that emerge vertically from a central meristem. Ramets often produce a single, erect, monoecious flowering stem consisting of a staminate spike above a pistillate spike. At maturity, ramets can collapse from wind, or under their own weight (S Hall, University of Wisconsin, USA, personal communication, 2008). Rhizomes often measure several centimeters in diameter and produce abundant adventitious roots. Smith (1967, 2000) distinguished T. domingensis from similar species primarily on the basis of pistillate spike characters. T. domingensis is characterized by: pistillate bracteoles pale to light brown, slightly exceeding pistil hairs in mature spikes;pistil hair apices colorless to orange;stigmas linear to lanceolate, slightly exceeding bracteoles in mature spikes;pistillate spikes at anthesis cinnamon to light-brown, darkening slightly at maturity;monad pollen;staminate bracteoles (scales) straw to orange-brown colored;mucilage glands present on the adaxial surface of leaf sheathes and adjacent blades. Leaves are 6-18 mm wide, mature pistillate spikes are 13-26 mm wide, and the pistillate and staminate spikes are separated by a gap of 0-8 cm. Some quantitative macroscopic characters including spike width, gap length between pistillate and staminate spikes, and leaf width are useful, but are too variable for conclusive identification, which depends on the above microscopic floral characteristics. Finlayson et al. (1985) combined measurements of the gap between male and female inflorescences with the length and diameter of the female inflorescences to distinguish T. domingensis from T. orientalis in Australia.

Impact

T. domingensis can spread prolifically by rhizomes after seedlings establish in disturbed vegetation, often forming monotypes that reduce wetland plant and animal diversity. The species thrives under eutrophic conditions and artificially stabilized hydroperiods, but in undisturbed, low-nutrient wetlands, T. domingensis often grows sparsely and does not appear to reduce diversity. T. domingensis is economically important in many regions as a weaving material, but when invasive, the species can replace other valuable plant commodities. Short-term Typha control is provided by cutting, burning, or grazing, each followed by flooding, or herbicide, but re-growth from rhizomes and a vast soil seed-bank complicate eradication.

Hosts

T. domingensis can invade the margins of rice fields and lacustrine cornfields (Sykes 1981, cited in Finlayson et al., 1983;Hall, 2008).
Host Plants and Other Plants Affected
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Plant name|Family|Context
Oryza sativa|
Zea mays subsp. mays (sweetcorn)|Poaceae
Biology and Ecology
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Genetics
T. domingensis readily hybridizes with other sympatric species of Typha. T. domingensis x latifolia has mostly abortive pollen and low seed set, while T. angustifolia x domingensis (reported in France and California) is highly fertile and can form hybrid swarms (Geze, 1912, cited in Smith, 1987;Smith, 1967). T. domingensis, T. latifolia, and T. angustifolia share n=15 chromosomes (Smith, 1967). T. domingensis shows ecotypic variation for a number of traits, including salt tolerance, germination temperature, time of flowering, height, rhizome proliferation, and rhizome number (McNaughton, 1966). Because of the worldwide distribution of T. domingensis, quantitative data presented here will likely vary widely among regional ecotypes.
Reproductive Biology
T. domingensis is protogynous, self-compatible, and does not show apomixis (Smith, 1967). Pollen requires strong winds for dispersal, and T. latifolia pollen can travel distances of at least one km (Krattinger, 1975). Despite copious pollen production, self-pollination appears to exceed outcrossing even in dense stands of T. latifolia. Some populations of T. domingensis remain in anthesis for more than a month (McNaughton, 1966). Each inflorescence can produce 600,000 fruits, or 6-17 million seeds per m 2 depending on flowering ramet density, and plants established from seed can flower by the second year (Prunster, 1940, cited in Finlayson et al., 1983;Howard-Williams, 1975). Germination can occur year-round in many climates, given adequate moisture, although germination declines below 20 ° C (Finlayson et al., 1983). In the United States, southern populations germinated at a lower temperature (13 ° C) than their northern counterparts (McNaughton, 1966). Seeds germinate under moist or submerged conditions;in an extreme case, T. domingensis germinated under 80 cm of water and survived for 8 weeks (Nicol and Ganf, 2000). Salinity reduces germination, although limited germination can occur even at 20% salinity (Beare and Zedler, 1987). High salinity prevented T. domingensis from recruiting after a lake drawdown in Malawi (Howard-Williams, 1975). Exposure to light and hypoxia increase germination (Sifton, 1959), which is low under established vegetation (Finlayson et al., 1983). In natural areas not disturbed by humans, disturbance and herbivory by animals could facilitate seedling establishment of Typha seedlings (Svengsouk and Mitsch, 2001).
Lateral rhizomes can facilitate rapid vegetative expansion after seedling establishment. Individual T. latifolia clones can span 60 m (Krattinger, 1983), and T. domingensis can spread laterally at 3-10 m/year (Parsons and Cutherbertson, 1992;Fraga and Kvet, 1993). Rhizome production is stimulated by short days and cold temperatures (McNaughton, 1966).
Physiology and Phenology
In frost-free climates, T. domingensis can produce ramets (culms) year-round, although most emerge in summer and autumn, and do not survive longer than 10 months (Finlayson et al., 1983;Parsons and Cuthbertson, 1992). In a spring-fed wetland in central Mexico, T. domingensis growing in dense stands did not produce new ramets between May and October unless disturbed by leaf harvest (Hall et al., in press). Flowering ramets differentiate by spring, and become fertile by early summer. Grace and Harrison (1986) contend that high rhizome carbohydrate supplies promote Typha ramets to flower rather than to remain vegetative. Repetitive harvesting decreased rhizome starch reserves and flowering ramet density of T. domingensis, but drought stress could promote flowering (Hall, 2008). Carbohydrate dynamics have been studied for T. latifolia. Leaf biomass is at a maximum while rhizome biomass is minimized in late summer. By autumn, leaf carbohydrates have been translocated to rhizomes, biomass increases, and rhizome starch concentrations are maximized (Linde et al., 1976). For T. domingensis in Belize, leaf turnover averages 110 days (Rejmankova et al., 1996). Fraga and Kvet (1993) report that T. domingensis in Cuba had a net primary productivity of 1500 g/m 2 /year. Litterbag experiments showed only 50% decomposition after one year, and organic matter accumulated rapidly.
In flooded conditions, oxygen is conducted to Typha ’s underwater tissues via leaf aerenchyma cells (Sale and Wetzel, 1983), allowing T. domingensis to tolerate water 2 m deep (Finlayson et al., 1983). Flooded seedlings only produced additional ramets, however, when they reached the water surface (Nicol and Ganf 2000). T. domingensis is moderately salt-tolerant, and salinities of up to 5% should not impede vegetative growth or flowering. Salinity 5% prevents growth, and salinity 25% causes leaf mortality, although rhizomes re-sprout if salinity declines (Beare and Zedler, 1987). Freshwater inflows lasting 2 months allowed T. domingensis to invade California salt marshes. T. domingensis thrives in hot climates, and grows well in water at 30 ° C (Finlayson et al., 1983). Parsons and Cuthbertson (1992) reported maximum growth at 32 ° C, declining to 50% at 18 ° C. Typha spp. show a high tolerance for soil and water contaminated by heavy metals (McNaughton et al., 1974).
Nutrition
T. domingensis thrives under high nutrient loads and stable, prolonged, hydroperiods. In the Florida Everglades, T. domingensis invasion correlated with increased phosphorus and water levels, and muck-burning fires (Urban et al., 1993;Newman et al., 1998). Typha ’s limitation by phosphorus is supported by a comparison of soil and plant tissue samples from eutrophic and un-impacted areas of the Everglades (Koch and Reddy, 1992). T. domingensis also appeared limited by phosphorus in wetlands of Mexico’s Yucatan Peninsula and Belize (Rejmankova et al., 1996). In mesocosms, elevated nutrient levels and prolonged hydroperiods increased T. domingensis biomass and tissue phosphorus concentration relative to the co-occurring Cladium jamaicense (Newman et al., 1996). Substantial peat, nitrogen, and phosphorus accumulated where T. domingensis dominated nutrient-rich areas of the Everglades (Craft and Richardson, 1993). Seedlings produced more biomass, had a greater root/shoot ratio, and contained more phosphorous when grown in burned soil than in unburned or surface-burned soil in the Everglades, suggesting that soil-burning fires promote T. domingensis by releasing phosphorus (Smith and Newman, 2001). In low-nutrient areas of the Everglades, Typha is present but does not dominate (Davis, 1994).
Nitrogen and phosphorus appeared to co-limit the congener T. latifolia when it was grown in mesocosms, whereas in the field, T. latifolia increased along a gradient of increasing phosphorus (Svengsouk and Mitsch, 2001). T. x glauca required both nitrogen and phosphorus for growth in a greenhouse experiment, but adding a higher proportion of phosphorus stimulated growth regardless of nutrient concentration (Woo and Zedler, 2002).
Associations
In disturbed and eutrophic wetlands, T. domingensis tends to form monotypes. However, T. x glauca ’s invasive growth may be dependent on anthropogenic modifications (e.g. from dams, wastewater discharge, or irrigation canals). In little-disturbed wetlands where hydroperiods fluctuate seasonally, many genera co-occur with T. domingensis. In Australian wetlands, Baumea, Eleocharis, Gahnia, Melaleuca, Muehlenbeckia, and T. orientalis co-dominate with T. domingensis where water levels fluctuate (Finlayson et al., 1983;Nicol and Ganf, 2000). In Cuba, Bidens, Cyperus, Eleocharis, Hyparrenia, Panicum, and Sagittaria can co-occur with T. domingensis in shallow water, although T. domingensis often forms temporary monotypes in deeper water (Fraga and Kvet 1993). In this system, shrubs can replace Typha because of rapid organic matter accumulation;frequent fire might reduce litter and retard succession. In Africa’s Lake Victoria, T. domingensis is less abundant than the dominant Cyperus or Miscanthidium (Kansiime et al., 2007);in Lake Chad, Vossia, Cyperus, and Phragmites dominate, while T. domingensis is rare (Denny, 1985a). Thompson (1985) ranked T. domingensis as the third most-dominant African wetland plants, behind Phragmites australis and P. mauritianus. In Belize, T. domingensis normally dominates on clay soils with low salinity, while growing sparsely with dominant Eleocharis and Cladium on marl and sandy soil with higher salinity (Rejmankova et al., 1996). T. domingensis monotypes in this region may be relics of phosphorus-rich agricultural run-off. In Iran, T. domingensis and Schoenoplectus tabernaemontani co-dominate diverse wetlands (Karami et al., 2001). In a groundwater-fed wetland in central Mexico, harvesting T. domingensis increased species richness and the recruitment of uncommon species (Hall, 2008). Here, more than 40 species co-occurred with Typha and the co-dominant Schoenoplectus americanus.
Environmental Requirements
T. domingensis tolerates a broad climatic spectrum, growing between 40 ° latitude north and south under a variety of rainfall regimes (Smith, 2000). Although T. domingensis tolerates widely variable hydroperiods, it can decline during extended drawdowns, and grows best under flooded conditions (Rejmankova et al., 1996;Palma-Silva et al., 2005). Rainfall does not appear to limit wide-scale geographic distribution, because even in seasonally dry climates (e.g. central Mexico), T. domingensis can persist in isolated springs or on lakeshores. Seedlings can tolerate anaerobic conditions, but mature plants are intolerant of anaerobic conditions created when leaves are severed below water (Sale and Wetzel, 1983).
Climate
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Climate|Status|Description|Remark
Af - Tropical rainforest climate| Preferred
60mm precipitation per month
Am - Tropical monsoon climate| Preferred
Tropical monsoon climate (60mm precipitation driest month but (100 - [total annual precipitation(mm}/25]))
As - Tropical savanna climate with dry summer| Preferred
60mm precipitation driest month (in summer) and (100 - [total annual precipitation{mm}/25])
Aw - Tropical wet and dry savanna climate| Preferred
60mm precipitation driest month (in winter) and (100 - [total annual precipitation{mm}/25])
BS - Steppe climate| Preferred
430mm and 860mm annual precipitation
BW - Desert climate| Preferred
430mm annual precipitation
C - Temperate/Mesothermal climate| Preferred
Average temp. of coldest month 0°C and 18°C, mean warmest month 10°C
Cf - Warm temperate climate, wet all year| Preferred
Warm average temp. 10°C, Cold average temp. 0°C, wet all year
Cs - Warm temperate climate with dry summer| Preferred
Warm average temp. 10°C, Cold average temp. 0°C, dry summers
Cw - Warm temperate climate with dry winter| Preferred
Warm temperate climate with dry winter (Warm average temp. 10°C, Cold average temp. 0°C, dry winters)
Latitude/Altitude Ranges
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Latitude North (°N)|Latitude South (°S)|Altitude Lower (m)|Altitude Upper (m)
40
40
0
0
Soil Tolerances
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Soil drainage
impeded
seasonally waterlogged
Soil reaction
acid
alkaline
neutral
Soil texture
heavy
light
medium
Special soil tolerances
infertile
other
saline
shallow
sodic
Notes on Natural Enemies
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Herbivory is common but variable. In Australia, kangaroos, rodents, and water birds lightly graze T. domingensis, while water buffalo can cause heavy damage (Finlayson et al., 1983). In Africa, large herbivores do not extensively feed on T. domingensis, despite its abundance (Howard-Williams and Gaudet 1985). In Costa Rica and elsewhere throughout Latin America, cattle heavily graze T. domingensis (McCoy et al., 1994). Muskrats (Ondatra zibethicus) can eliminate entire stands of Typha spp. through herbivory, at least in temperate climates (Kadlec et al., 2007). Barreto et al. (2000) mention a variety of fungal pathogens, although none have been extensively studied in the field. A variety of insects feed on T. latifolia and T. angustifolia. Lepidopteran larvae often inhabit inflorescences, while noctuid caterpillars and coleoptera attack leaves, stalks, and sometimes rhizomes (Grace and Harrison, 1986).
Means of Movement and Dispersal
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Natural Dispersal (Non-Biotic) Typha ’s tiny seeds (1 - 2 mm long) are contained in achenes attached to pistil hairs, and are often dispersed by the wind. Spikes do not shed fruits until they have dried (Krattinger, 1975), often delaying dispersal until many months after seed maturation. The entire female spike sometimes collapses in place, providing a floating platform for germination (Hall, 2008). Masses of achenes and hairs, and rhizomes, can disperse by floating on currents of water (Grace and Harrison 1986;Parsons and Cutherbertson, 1992).
Vector Transmission (Biotic)
When achenes are moistened, seeds are released, which have a pointed end that can become embedded in fish scales (Krattinger, 1975). Also, pistil hairs (with attached acenes) adhere to the clothing of fieldworkers, and could attach to animals as well (S Hall, University of Wisconsin, USA, personal communication, 2008). Mud with embedded seeds readily sticks to humans, livestock, birds, and agricultural implements (Parsons and Cuthbertson, 1992).
Intentional Introduction
Indigenous people in the Northwestern United States propagated T. latifolia using rhizome fragments (Turner and Peacock, 2005). Similar propagation of T. domingensis has not been documented.
Pathway Causes
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Cause|Notes|Long Distance|Local|References
Crop production|Seeds attach to mud on agricultural implements.| Yes
Parsons and Cuthbertson,
1992
Disturbance|Seedlings establish in disturbed vegetation.| Yes
Finlayson et al.,
1983
Hitchhiker|Achenes with hairs attach to humans and animals.| Yes
Yes
Parsons and Cuthbertson,
1992
Interbasin transfers|Achenes and rhizomes disperse with water currents.| Yes
Grace and Harrison,
1986;Parsons and Cuthbertson,
1992
Interconnected waterways|Achenes and rhizomes disperse with water currents.| Yes
Grace and Harrison,
1986;Parsons and Cuthbertson,
1992
Self-propelled|Achenes with hairs are wind-dispersed.| Yes
Krattinger,
1975
Pathway Vectors
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Vector|Notes|Long Distance|Local|References
Clothing, footwear and possessions|Achenes with hairs.| Yes
Parsons and Cuthbertson,
1992
Host and vector organisms|Achenes adhere to fish scales.| Yes
Krattinger,
1975
Water|Achenes with hairs, rhizomes.| Yes
Grace and Harrison,
1986;Parsons and Cuthbertson,
1992
Wind|Achenes with hairs.| Yes
Yes
Krattinger,
1975
Impact Summary
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Category|Impact
Economic/livelihood
Positive and negative
Environment (generally)
Positive and negative
Economic Impact
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T. domingensis can interfere with agriculture in wet areas. With the adoption of year-round rice cropping in Australia, T. domingensis invaded fields and decreased yields by 5% (Sykes 1981, cited in Finlayson et al., 1983). In central Mexico’s Lake Pátzcuaro, T. domingensis can invade low-lying cornfields. This species also tends to replace the bulrush Schoenoplectus californicus, a valuable species traditionally used to weave mats (Hall, 2008). In southern Mexico, T. domingensis invades wetlands used for horse pasture, and replaces valuable fodder (S Hall, University of Wisconsin, USA, personal communication, 2009). In lacustrine wetlands, T. domingensis can interfere with fishing and water transportation (Mitchell, 1985).


Source: cabi.org
Description

T. latifolia is an erect thick-stemmed perennial with flowers consisting of cylindrical spikes, and stems 1-3 m tall. Linear, light green, flat leaves with a sheath at the base, extending to flowering spikes, 15-25 mm wide (Grace and Harris, 1986). Fibrous roots grow from rhizomes produced at base of leaves. Rhizomes are as long as 70 cm, 0.5-3 cm in diameter. Unisexual flowers include a pistillate portion below the staminate portion, forming a continuous spike 12-35 mm in diameter. Spike goes from green to brown as ripening occurs. Staminate flowers have hair-like bracteoles;bracteoles absent in pistillate flowers. Pollen grains formed in tetrads. Over 1000 flowers may be produced on one plant. Nutlike achenes about 1.5 mm long are derived from fertilized flowers. Seeds eventually break off generally by wind or water and are transported via long slender hairs (Hitchcock and Cronquist, 1973;Grace and Harrison, 1986;Welsh et al., 1987;Hickman, 1993;Larson, 1993;Pojar and MacKinnon, 1994).

Recognition

A survey was conducted among people in the aquatic plant trade in New Zealand (Champion and Clayton, 2001), and in the process provided information on identification so that T. latifolia could be distinguished from the native Typha species, T. orientalis (Champion et al., 2007). In particular,characteristics used to distinguish T. latifolia were: leaf sheaths tapering to lamina, female flower lacking scales, female spike dark brown, male and female spikes of similar lengths, and the grouping of pollen grains in tetrads. The identification utilized literature resources such as Fassett and Calhoun (1952), Aston (1973), Tutin et al. (1980), and Smith (1967a,b). The two species as well as T. laxmannii, another potential invader of New Zealand, are illustrated in Champion et al. (2007).

Impact

T. latifolia is a cosmopolitan plant, occurring in wetlands through most temperature zones in North America, Europe and Asia, and many subtropical areas. It has also begun to invade the few regions where it is not native, e.g., Oceania, South-East Asia and the Hawaiian islands. It forms dense populations under suitable conditions, often as monocultures excluding other species of vegetation. Holm et al. (1997) designated it as one of the “World’s Worst Weeds”. T. latifolia can reduce rice production, impact wildlife populations and can alter nutrient cycles negatively. In New Zealand it is classed as an “unwanted organism” as part of the National Plant Pest Accord (Champion et al., 2007). Potential for rapid clonal growth and long persistence of T. latifolia in areas where it is native presents a warning against establishment of this species in areas where it is not native and would impact native biodiversity.


Source: cabi.org
Description

Adult Papuana huebneri are black, shiny and 15-20 mm long. The size and number of head horns in taro beetles varies between species and sexes;P. huebneri has only one small horn, which is larger in the male than the female (Macfarlane, 1987a).

Recognition

Taro beetles can be detected by: (1) digging up wilting taro plants and examining them for signs of damage;(2) using light traps, particularly on moonless and rainy nights;and (3) sampling wild plant species (e.g. banana, sugarcane and grasses such as Paspalum spp. and Brachiaria mutica) at breeding sites, especially along river banks, on rotting logs and in compost heaps (Carmichael et al., 2008;Tsatsia and Jackson, 2014;TaroPest, 2015).

Symptons

Adult taro beetles burrow into the soft trunks, plant bases and corms of a range of plants, including taro, making large holes or cavities up to 2 cm in diameter (McGlashan, 2006). The feeding tunnels and associated frass may be visible in infested corms (Biosecurity Australia, 2011). The amount of damage to the crop depends on the age of the plants when attacked and the density of infestation. Feeding activity can cause wilting and even the death of affected plants, particularly in young plants if the beetles bore into the growing points. Older plants infested by beetles grow slowly and a few or all of the leaves wilt (TaroPest, 2015). In severely damaged plants tunnels may run together to form large cavities, making the damaged corms more susceptible to fungal infections (Macfarlane, 1987a;Onwueme, 1999). Similar symptoms of damage are caused to other root crops, e.g. sweet potato, yams and potato (McGlashan, 2006). Taro beetles can ring-bark young tea, cocoa and coffee plants in the field and bore into seedlings of oil palm and cocoa (Aloalii et al., 1993).

Impact

Papuana huebneri is one of at least 19 species of known taro beetles native to the Indo-Pacific region;it is native to Papua New Guinea, the Molucca Islands in Indonesia, the Solomon Islands and Vanuatu, and has been introduced to Kiribati. Taro (Colocasia esculenta) is an important crop in these countries;high infestations of P. huebneri can completely destroy taro corms, and low infestations can reduce their marketability. The beetle also attacks swamp taro or babai (Cyrtosperma chamissonis [ Cyrtosperma merkusii ]), which is grown for consumption on ceremonial occasions. Infestations of taro beetles, including P. huebneri, have led to the abandonment of taro and swamp taro pits in the Solomon Islands and Kiribati, resulting in the loss of genetic diversity of these crops and undermining cultural traditions. P. huebneri also attacks a variety of other plants, although usually less seriously. Management today relies on an integrated pest management strategy, combining cultural control measures with the use of insecticides and the fungal pathogen Metarhizium anisopliae.

Hosts

Papuana huebneri is a pest of taro (Colocasia esculenta;known as ‘dalo’ in Fijian;McGlashan, 2006) (Masamdu, 2001;International Business Publications, 2010), which is grown primarily as a subsistence crop in many Pacific Island countries, including Kiribati, Papua New Guinea, the Solomon Islands and Vanuatu, where P. huebneri is found (Aloalii et al., 1993). Taro also has value in gift-giving and ceremonial activities (Braidotti, 2006;Lal, 2008). The beetle also attacks swamp taro or babai (Cyrtosperma merkusii or Cyrtosperma chamissonis), which is grown for consumption on ceremonial occasions (Food and Agriculture Organization, 1974;Dharmaraju, 1982;International Business Publications, 2010).
Other plants attacked by Papuana huebneri include tannia (Xanthosoma sagittifolium), bananas (Musa spp.), Canna lily (Canna indica), pandanus (Pandanus odoratissimus [ Pandanus utilis or P. odorifer ]), the bark of tea (Camellia sinensis), coffee (Coffea spp.) and cocoa (Theobroma cacao), the fern Angiopteris evecta (Masamdu, 2001), and occasionally the Chinese cabbage Brassica chinensis [ Brassica rapa ] (International Business Publications, 2010).
Species of Papuana behave similarly to each other and feed on the same host plants (TaroPest, 2015). For taro beetles in general, primary host plants other than taro include giant taro (Alocasia macrorrhizzos), Amorphophallus spp., the fern Angiopteris evecta, banana (Musa spp.) and tannia (Xanthosoma sagittifolium). Secondary hosts include pineapple (Ananas comosus), groundnut (Arachis hypogaea), betel nut (Areca catechu), cabbage (Brassica oleracea), canna lily (Canna indica), coconut (Cocos nucifera), Commelina spp., Crinum spp., yam (Dioscorea spp.), oil palm (Elaeis guineensis), sweet potato (Ipomoea batatas), Marattia spp., pandanus (Pandanus odoratissimus [ Pandanus utilis or P. odorifer ]), Saccharum spp. including sugarcane (Saccharum officinarum) and Saccharum edule [ Saccharum spontaneum var. edulis ], and potato (Solanum tuberosum);they occasionally ring bark young tea (Camellia sinensis), coffee (Coffea spp.) and cocoa (Theobroma cacao) plants (Macfarlane, 1987b;Aloalii et al., 1993;Masamdu and Simbiken, 2001;Masamdu, 2001;Tsatsia and Jackson, 2014;TaroPest, 2015).


Source: cabi.org
Description


In life, adult females are oval, up to 5 mm long, greyish-yellow, with two longitudinal, submedian, interrupted dark stripes on the dorsum showing through the waxy secretion -- hence the common name 'striped mealybug'. The dorsum also bears numerous straight, glassy threads of wax up to 4.0-4.5 mm long. Several members of the genus Ferrisia have this appearance in life, so authoritative identification requires expert study of stained, slide-mounted adult females using the key in Kaydan and Gullan (2012), or nucleotide sequence data.
Slide-mounted adult female Ferrisia species are easy to recognise by the presence of only one pair of cerarii, situated on the anal lobes, and the presence of enlarged tubular ducts, each with the orifice surrounded by a flat, circular, sclerotized area associated with one or more short setae. Kaydan and Gullan (2012) provided a thorough revision of the genus Ferrisia and a morphological key to world species, including detailed morphological description, illustration and discussion of F. virgata. F. virgata is very difficult to separate from some of the other species, particularly F. dasylirii. It has both anterior and posterior pairs of ostioles;ventral oral-collar tubular ducts of at least 2 sizes;smaller ducts present singly or in segmental clusters on body margin, only on last 2–3 abdominal segments;minute discoidal pores in sclerotised area of enlarged dorsal tubular ducts and larger ventral oral-collar tubular ducts rarely if ever touching rim of duct opening (or only very rarely on ventral ducts);discoidal pores associated with sclerotised area around orifices of dorsal enlarged tubular ducts on anterior abdomen normally not touching outer margin of sclerotised area and very rarely projecting from that margin;dorsal enlarged tubular ducts numbering 69-101;abdominal segment VI with 11-28 multilocular disc pores, usually with more than 15 in a double row;each anal lobe cerarius with 3 (occasionally 2) enlarged conical setae;and hind coxa with translucent pores (Kaydan and Gullan, 2012).

Recognition


Heavy infestations are conspicuous because of the white waxy secretions, white masses of male tests (waxy filamentous cocoons) and sooty moulds growing on the excreted honeydew. Colonies often occur at the growing points, around the stem nodes, on the undersides of leaves and on the fruit.

Symptons


Infestations of F. virgata remain clustered around the terminal shoots, leaves and fruit, sucking plant sap which results in yellowing, withering and drying of plants and premature shedding of leaves and fruit. The mealybugs do not feed on phloem very often, so unlike many mealybug species they do not produce huge quantities of sugary honeydew. What honeydew is produced can foul foliage and fruit and serve as a medium for the growth of black sooty moulds. Sooty moulds and wax deposits can block light and air from the plant, sometimes reducing photosynthesis and hence plant vigour and crop yield.

Impact

Ferrisia virgata is a highly polyphagous mealybug. It reproduces quite rapidly in tropical conditions, but it tolerates subtropical and to some extent temperate conditions too. It has been reported on host-plants belonging to over 203 genera in 77 families, and can damage many crops, particularly tropical fruit, nut and spice crops and field crops like soybean and tomato. It is known to transmit plant badnavirus diseases of cocoa and black pepper. It is of Neotropical origin and spread around the world in only about 10 years after being first described from Jamaica. Its polyphagy has facilitated its spread by human transport of infested plants, and it is now established in all the subtropical and tropical zoogeographic regions. Its small size and cryptic habits make it difficult to detect and identify at plant quarantine inspection. The increase in international trade in fresh plant material in recent years is likely to facilitate its continued spread.

Hosts

F. virgata is one of the most highly polyphagous mealybugs known, attacking plant species belonging to some 203 genera in 77 families (García et al., 2016). Many of the host species belong to the Fabaceae and Euphorbiaceae. Among the hosts of economic importance are avocado, banana, betel vine, black pepper, cassava, cashew, cauliflower, citrus, cocoa, coffee, cotton, custard apple, aunergine, grapevine, guava, jute, lantana, Leucaena, litchi, mango, oil palm, pigeon pea, pineapple, soyabean and tomato. Acalypha species are apparently a favoured host-plant in many places (Kaydan and Gullan, 2012).


Source: cabi.org
Description

Workers of the pharaoh ants (Monomorium pharaonis) are approximately 2mm in length and have body colours ranging from light-brown to red. The males are the same size as the workers but are black in colour. The queens are 4mm in length and slightly darker than the workers (Nickerson and Harris 2003).

Impact

Monomorium pharaonis the pharaoh ant) is native to Africa and has successfully invaded areas on every continent except Antarctica. It is concentrated in tropical regions but is also commonly found in temperate zones within suitable human infrastructure, especially buildings associated with the distribution or storage of food. Due to Monomorium pharaonis' ability to act as a vector for some bacterial human pathogens, its presence in hospitals is of great concern as it may increase infection rates.


Source: cabi.org
Description

A. fulica is distinctive in appearance and is readily identified by its large size and relatively long, narrow, conical shell. Reaching a length of up to 20 cm, the shell is more commonly in the size range 5-10 cm. The colour can be variable but is most commonly light brown, with alternating brown and cream bands on young snails and the upper whorls of larger specimens. The coloration becomes lighter towards the tip of the shell, which is almost white. There are from seven to nine spirally striate whorls with moderately impressed sutures. The shell aperture is ovate-lunate to round-lunate with a sharp, unreflected outer lip. The mantle is dark brown with rubbery skin. There are two pairs of tentacles on the head: a short lower pair and a large upper pair with round eyes situated at the tip. The mouth has a horned mandible, and a radula containing about 142 rows of teeth, with 129 teeth per row (Schotman, 1989;Salgado, 2010). Eggs are spherical to ellipsoidal in shape (4.5-5.5 mm in diameter) and are yellow to cream in colour.

Recognition

A. fulica is a large and conspicuous crop pest which hides during the day. Surveys are best carried out at night using a flashlight. It is easily seen, and attacked plants exhibit extensive rasping and defoliation. Weight of numbers can break the stems of some species. Its presence can also be detected by signs of ribbon-like excrement, and slime trails on plants and buildings.

Symptons

In garden plants and ornamentals of a number of varieties, and vegetables, all stages of development are eaten, leading to severe damage in those species that are most often attacked. However, cuttings and seedlings are the preferred food items, even of plants such as Artocarpus which are not attacked in the mature state. In these plants damage is caused by complete consumption or removal of bark. Young snails up to about 4 months feed almost exclusively on young shoots and succulent leaves. The papaya is one of the main fruits which is seriously damaged by A. fulica, largely as a result of its preference for fallen and decaying fruit.
In plants such as rice, which are not targets of A. fulica, sometimes sheer weight of numbers can result in broken stems. In general, physical destruction to the cover crop results in secondary damage to the main crop, which relies on the cover crop for manure, shade, soil and moisture retention and/or nitrogen restoration. This in turn can result in a reduction in the available nitrogen in the soil and consequently marked erosion in steeper areas.

Impact


The giant African land snail A. fulica is a fast-growing polyphagous plant pest that has been introduced from its native range in East Africa to many parts of the world as a commercial food source (for humans, fish and livestock) and as a novelty pet. It easily becomes attached to any means of transport or machinery at any developmental stage, is able to go into a state of aestivation in cooler conditions and so is readily transportable over distances. Once escaped it has managed to establish itself and reproduce prodigiously in tropical and some temperate locations. As a result, A. fulica has been classified as one of the world's top 100 invasive alien species by The World Conservation Union, IUCN (ISSG, 2003).

Hosts

A. fulica is a polyphagous pest. Its preferred food is decayed vegetation and animal matter, lichens, algae and fungi. However, the potential of the snail as a pest only became apparent after having been introduced around the world into new environments (Rees, 1950). It has been recorded on a large number of plants including most ornamentals, and vegetables and leguminous cover crops may also suffer extensively. The bark of relatively large trees such as citrus, papaya, rubber and cacao is subject to attack. There are reports of A. fulica feeding on hundreds of species of plants (Raut and Ghose, 1984;Raut and Barker, 2002). Thakur (1998) found that vegetables of the genus Brassica were the most preferred food item from a range of various food plants tested. However, the preference for particular plants at a particular locality is dependent primarily on the composition of the plant communities, with respect to both the species present and the age of the plants of the different species (Raut and Barker, 2002). Crops in the Poaceae family (sugarcane, maize, rice) suffer little or no damage from A. fulica.
Given the polyphagous nature of A. fulica any host list is unlikely to be comprehensive. Those plant hosts included in this datasheet have been found in literature searches and Venette and Larson (2004).


Source: cabi.org
Description

A. conyzoides is an erect, branching, annual herb with shallow, fibrous roots. It may, depending upon environmental conditions, reach 50-1500 mm tall at flowering. The stems, which may root where the bases touch the ground, are cylindrical, and become strong and woody with age;nodes and young parts of the stem are covered with short, white hairs. Leaves are opposite, 20-100 mm long, 5-50 mm wide, on hairy petioles 5-75 mm long, broadly ovate, with a rounded or narrowed acute base and an acute or obtuse or sometimes acuminate tip and toothed margins. Both leaf surfaces are sparsely hairy, rough with prominent veins and when crushed the leaves have a characteristic odour which is reminiscent of the male goat. The branched, terminal or axillary inflorescence bears 4-18 flower heads arranged in showy, flat-topped clusters. Individual flower heads are light blue, white or violet, are carried on 50-150 mm long peduncles and are 5 mm across, 4-6 mm long with 60-75 tubular flowers. The flower head is surrounded by two or three rows of oblong bracts which are green with pale or reddish-violet tops. The bracts are 3-5 mm high, outer ones 0.5-1.75 mm wide, sparsely hairy, evenly toothed in the upper part, with an abruptly acuminate, acute tip. Flowers are 1.5-3 mm long and scarcely protrude above the bracts. The fruit is a ribbed or angled, black achene, 1.25-2 mm long, roughly hairy, with a pappus of 5, rarely 6, rough bristles, white to cream coloured, 1.5-3 mm long with upward turning spines.

Impact

A. conyzoides is an annual erect herb reported as an invasive, noxious weed in agricultural lands and as a coloniser of open fields and degraded areas, causing crop yield reductions and affecting biodiversity (Kohli et al., 2006;GISD, 2016;PIER, 2016). It is also a host of pathogens and nematodes that affect crop species (BioNET-EAFRINET, 2016). It is listed as invasive throughout Asia;in Kenya, Mayotte, Morocco, Reunion, Tanzania, South Africa and Uganda in Africa;California (USA) in North America;Cuba in the Caribbean;Easter Island in South America;and in much of Oceania (Oviedo-Prieto et al., 2012;BioNET-EAFRINET, 2016;Encylopedia of Life, 2016;GISD, 2016;PIER, 2016). It is also known to be invasive in Ethiopia, Malawi, Rwanda, and Zambia.

Hosts

A. conyzoides is a common weed of plantation crops and overgrazed pastures but can also be found in the important tropical and subtropical annual crops of rainfed or irrigated dryland systems. It has been reported from 36 different crops in 46 countries (Holm et al., 1977).


Source: cabi.org
Description

A. sessilis is an annual or perennial herb, of 0.2-1 m high, with strong taproots. The stems are generally prostrate, creeping, often rooting at the nodes, sometimes floating or ascending at the tips, cylindrical and slightly hairy, with numerous, erect branches. The leaves are simple, opposite, shortly petiolate or sessile, broadly lanceolate or spatulate to almost linear, 0.6-5 cm long, and 0.3-1 cm wide. They are attenuated at the base, and the apex is acute to blunt, with entire, glabrous or pilose (thin, fine, articulate hairs) margins. The inflorescences are dense, sessile, silvery-white clusters of compressed spikes in the leaf axils;perianth segments are equal in length, acute, 1.5-2.5 mm long with a short point. Bracts are ovate, concave, 0.3-1 mm long and persistent;bracteoles are oblong-ovate, 1-1.5 mm long, may be acute, and not deeply lacerated. Sepals are 2-3 mm long, white or purplish, glossy with a green base, glabrous or with a few long hairs, and a strong midrib. The fruits are indehiscent, a small, flattened, obcordate or obovate utricle, 2-2.5 mm long, enclosing the seed. Seeds are dark-brown to black, disc-shaped and shiny, about 0.8-1 mm in diameter. They are light sensitive and the average number of seeds per plant is ca 2000.

Impact

A. sessilis is a pioneer species typically growing on disturbed areas and in wetland habitats, and regarded as a fast-growing highly invasive weed. It is adapted to grow on a range of soil types ranging from poor sandy or alkaline soils, to loam or black cotton soils. It is also able to grow in seasonally-waterlogged areas as well as in areas with extreme dry conditions (Holm et al., 1997). A. sessilis can be found invading floodplain wetlands, margins of rivers, streams, canals, ditches, ponds, reservoirs, tanks, marshes, swamps, wet low-lying ground, ephemeral pools, seasonal pans and damp forest. This species is also a weed in fields with sorghum, millet, Eleusine spp., maize, cotton, cassava, cereal crops, pastures, and vegetable farms (Gupta, 2014). Consequently, this species has been listed as invasive in India, South Africa, Namibia, Spain, Hawaii and many other islands in the Pacific Ocean (see distribution table for details). It is also listed as a noxious weed in the United States (USDA-NRCS, 2014).


Source: cabi.org
Description

D. ciliaris is an annual grass, typically decumbent, rooting at the nodes and spreading to form untidy patches up to 1 m across and 50 cm high, although under crowded conditions it will grow more erect with culms up to 1 m high. The leaves are up to 25 cm long and 1 cm wide. Sheaths and lower parts of leaves loosely hairy on both surfaces. Ligule membraneous, 1-3 mm long. Inflorescence on a long culm, usually much taller than the foliage, consists of 2-9 racemes 5-10(-15) cm long sub-digitate (the latin generic name means 'fingers') with one or more inserted up to 1 cm below the others. The rachis of the racemes is up to 1 mm wide. The spikelets, arranged in pairs, one sessile and the other shortly pedicelled, are 2.5-3.5 mm long, tapering to an acute tip. The lower glume is a very short but distinct scale about 0.3 mm long;the upper glume at least half, usually about 3/4 the length of the spikelet, with three nerves. The upper lemma is as long as the spikelet and has 5-7 nerves, usually with a distinct space each side of the central one. The lateral nerves are smooth, without the scabrid character of D. sanguinalis but are variable in hairiness, sometimes with very long hairs. The upper lemma is smooth with only one nerve, grey to light brown. Grain 1.5-2 mm long.

Hosts

D. ciliaris may occur in virtually any annual crop of the tropics and sub-tropics, and in most perennial crops and pastures. It is perhaps most conspicuous and troublesome in annual row-crops, including cereals, cotton, legumes and vegetables in which it establishes rapidly before the crop is casting adequate shade.


Source: cabi.org
Description

M. maximus is a robust, highly variable grass. It is a loosely to densely tufted perennial.
Vegetative morphology
M. maximus grows in densely tufted clumps with very short rhizomes;erect stems which are cylindrical, slightly flattened at the base, streaked with white wax at the nodes and internodes;glabrous internodes, hairy nodes, infrequently branched, up to 2.5 m. M. maximus is tall, usually 1-2 m tall. Light green, green or bluish-green leaves. The lower nodes of the stolons are rooted and can form new plants (Alves and Xavier, 1986).
Culms (25-)75-200(-450) cm high, erect from a shortly pubescent base or geniculately ascending and rooting at the lower nodes, slender to robust, branched or simple, glabrous to hispid or pilose, the lower nodes glabrous or bearded with soft, spreading hairs. Leaf blades linear to narrowly lanceolate, (6-)12-40(-100) cm long, (4-)12-35 mm wide, narrowed or straight at the base, flat membranous or herbaceous, glabrous or sparsely pilose to pubescent, acuminate (after Clayton et al., 1974).
Floral morphology
M. maximus has terminal, ovoid racemose panicles, 15-65 cm long, with brick-red spikelets when mature;spikelets roughly 3.5 mm long (Alves and Xavier, 1986).
Panicle oblong or pyramidal, 12-45(-60) cm long, usually much branched, the branches ascending to spreading, the lowest arranged in a whorl;pedicels and secondary branches fine and flexuous to fairly stiff and contracted. Spikelets oblong, (2.5-)3-4.5(-5) mm long, rounded on the back, glabrous or pubescent, blunt or acute, occasionally overtopped by long hairs from the tip of the pedicel;lower glume broadly ovate, one-third to one-half the length of the spikelet, 3-nerved, obtuse or acute;upper glume ovate-oblong, 5-nerved, acute;lower lemma ovate-oblong, 5-nerved;male rarely sterile, its palea well developed;upper lemma and palea conspicuously transversely rugose (after Clayton et al., 1974). The ligule is membranous with a ciliate margin, 1-3 mm long (Wagner et al., 1999).
[Note: Figures indicate normal range of sizes;those in brackets indicate the extremes of variation possible.]

Recognition


The appearance of some strains of M. maximus is so like that of sugarcane that they may be unnoticed until they flower (Holm et al., 1977).

Impact

M. maximus is a highly successful invader in tropical and warm temperate areas after introduction as fodder. It can spread from seed, is highly competitive with native flora, and while it is highly fire resistant it can quickly spread to invade gaps left in natural vegetation after fire.


Source: cabi.org
Description


Annual or short-lived perennial (some accounts clearly state one, the other or both) with basal buds (branching at base) laxly tufted often straggling with a short knotty rhizome as long as 4 cm. Culms erect or geniculate, 10-30-(75) cm, ± erect, nodes compressed, often dark brown, internodes ridged, glabrous, minutely prickle-toothed to pubescent on ridges just below panicle. Leaf sheaths keeled, glabrous (sometimes scabrous toward the summit);leaf blades stiff, flat or involute, (3)-8-15-(20) cm × 2-5 mm, glabrous or adaxial surface pilose at base, apex acuminate;ligule ca. 1 mm. Panicle densely cylindrical, 2–15 × 0.5–1.2 cm;branches reduced to a single mature spikelet subtended by 8–12 bristles;axis pubescent;bristles golden (yellow) or purplish brown when mature, 2–3 times spikelet length. Spikelets elliptic, 1.8–2.5 mm, light green, falling entire at maturity. lower glume ovate, approximately 1/3 as long as spikelet (0.7-1.2mm), 3 nerved acute or apiculate;upper glume broadly ovate, ca. 1/2 as long as spikelet 1-2 mm,3-(5) nerved, obtuse;lower floret neuter;lower palea firmly membranous, lanceolate, about as long as the upper floret but narrower, keels wingless, minutely papillose;upper lemma ovate-elliptic, finely rugulose, pale cream. Flowering and fruiting early autumn to early winter. This description combines sources (Hitchcock, 1931, 1971;Shouliang and Phillips, 2006;Edgar and Connor, 2010).

Recognition


Seed detection is described in Seed Regulatory and Testing Branch (2011). Field detection may be poor due to its similarity to other congeners (Dekker, 2003).

Impact

S. parviflora is a variable, self-compatible, rhizomatous, C4 plant with a short lived seed bank, commonly regarded as an agricultural weed both in its native and introduced range (Rabinowitz and Rapp, 1981;Pensiero, 1999;Mollard et al., 2007;Mollard and Insausti, 2011;Randall, 2012). It often colonizes cultivated and disturbed soils or waste places including seasonally wet sites and salt marshes (Hubbard, 1954;Leithead et al., 1971;Pott and Pott, 2004;Edgar and Connor, 2010). It can contaminate wool (Ryves et al., 1996), seed crops, especially those of grasses such as dryland rice, lawn seed and Bahia grass (Paspalum notatum) (Silveira Filho and Aquino, 1983;Wehtje et al., 2008;Seed Regulatory and Testing Branch, 2011) and degrade and dominate sod and pastures (including alfalfa), lowering hay quality, a problem because it can cause lesions in livestock (Murphy et al., 1992;Arregui et al., 2001;Muller and Via, 2012). Land infested with it might be considered to have lower value because of poor pasture. It is regarded as a member of the alien flora of Chile (Ugarte et al., 2011).

Hosts


Not usually a serious weed, except where it is a contaminant of seed crops (especially rice, lawn and forage grasses) and hay. Often management strategies focus on limiting seeding.


Source: cabi.org
Description

V. encelioides is an annual herb growing up to 150 cm high. Stems are densely short-hairy with mostly alternate leaves. Stems are 20-100 cm long. Leaf blades are lanceolate to triangular-ovate, bases broadly cuneate to truncate, dull green, 3-veined, with a coarsely dentate margin, and strigose-canescent hairs. The peduncle is subtended by leaf-like bracts. The inflorescence has 1-many heads with 1-2 phyllary series, 6-10 mm, and linear-lanceolate to linear. Chaff scales 6 to 8 mm and abruptly acuminate. Ray flowers are orange-yellow and disk flowers are yellow to light brown. Disk achenes are 4 to 6.5 mm, obovate, flattened, and with wide wing (Baldwin et al., 2012).

Recognition


One obvious character found on V. encelioides achenes are wings which can be used for identification (Coleman, 1966, 1974;Baldwin et al., 2012). For a description of the species with images refer to Feenstra and Clements (2008).

Impact

V. encelioides is a native annual herb in the USA and Mexico, but there exists controversy as to its native status in South America. It has expanded its range into Europe, Asia, Africa and Australia. Cause and timing of initial introductions are mostly unknown. It is considered invasive in the northern Hawaiian Islands due to the displacement of native plant species and the negative impacts it has on breeding colonies of marine birds. It is a dominant invasive on Midway Atoll (PIER, 2013). V. encelioides also invades agricultural crops, especially peanuts, in the United States, Argentina, Australia and India, where allelopathy may provide interference. When grazed upon by livestock (sheep and cattle), animals become lethargic or may die due to the toxin galegine in the plant.


Source: cabi.org
Description

M. nudiflora is an annual or perennial herb, 8-115 cm tall, with a basal leaf rosette, disappearing or absent in older plants, with one to several creeping leafy branches, being either erect, semi-erect, ascendant, or at the base. Leaves are alternately arranged, sessile, larger ones linear-lanceolate, smaller ones oblong-ovate, glabrous, or with sparsely-arranged trichomes or hairs, 1.7-28 or 1.7-45 cm x 5-25 mm, with a broad leaf base, acute apex, short leaf sheath, and villous. Roots are normal, not swollen. Inflorescences terminally- or axillary-arranged, either unbranched or with 2-3 branches, no large cucullate bracts;bracts 25-35 mm oblong-cucullate, rather thin, membranous, caducous, located at the base of 25-40 mm long, glabrous pedicels, sepals 3, green, oblong, obtuse, glabrous, 3.5-5.0 mm long, petals 3, oblong to ovate-oblong, obtuse, purplish to magenta in colour, 4.5-5.5 mm long. Stamens free, 2 fertile with densely long-hairy filaments and bluish-coloured anthers;staminoids 4, with long-bearded filaments, the 3 opposite the petals with thickened, 3-lobed, light yellow coloured top, the fourth much reduced in size. The ovary is glabrous. Fruits condensed, ellipsoid-globose, shortly acuminate, glabrous, 4-6 mm in diameter, 3-loculate, each cell with 1-2 seeds, rarely with more than 6 seeds per fruit. Seeds smooth to coarse reticulate, ribbed.

Impact

M. nudiflora is classified as one of the world's worst weeds by Holm et al. (1977), infesting no less than 16 crops in 23 countries. It is a major weed species in rice and other crops (Moody, 1989), and is a moderately invasive weed species both in agricultural crops and non-agricultural areas in South and South-east Asia (Waterhouse, 1993). Its special ability to root easily at the nodes, propagating clonally through cut stems and dispersal during tillage and land preparation make this weed difficult to control. This trait coupled with its ability to adapt and survive a wide ecological window of soil types, pH, moisture availability and soil drainage makes M. nudiflora a weed to watch for potential spread into new areas in near future, and a species under the 'alert list' by the Invasive Species Specialist Group. Oliveira Pellegrini et al. (2016) recognize M. nudiflora as one of two Murdannia species invasive in the Neotropics.

Hosts

M. nudiflora is a principal weed of peanuts, lowland and upland rice, tea, and maize in Indonesia, Philippines and Sri Lanka (Soerdarsan et al., 1974;Baki and Md Khir, 1983;Soerjani et al., 1987;Pancho and Obien, 1995). It is a weed of rice in the eastern plains of Colombia (Bastidas-Lopez, 1996;Plaza and Forero, 1998), bananas, citrus, sugarcane, vegetables, rice, maize and coffee in Mexico (Holm et al., 1977), pineapples in Hawaii, Indonesia, South Africa, Malaysia and the Philippines (Holm et al., 1977;Pancho and Obien, 1995;Baki et al., 1997), and taro in Fiji and Hawaii (Holm et al., 1977). Galinato et al. (1999) reported widespread occurrence of the weed in teak, tea, oil palm, chincona, cotton and coffee plantations, and in arable lands. In the United States, it has historically been a problematic weed in turfgrass systems, but it has become increasingly more common in North Carolina in cotton (Gossypium hirsutum) and soyabean (Glycine max) plantations (Wilson et al., 2006).


Source: cabi.org
Description

Adult
The adult is greyish brown with a 9-mm-long body and a wingspan of about 12-15 mm (Anonymous, 1983;Reid and Cuthbert, 1971). In males, upper (costal) two-thirds of forewings is light fuscous, sometimes partially ochre-tinged;sometimes mixed with whitish scales, and flecked with scanty small blackish dots. Lower one-third of the forewings is ochreous-white, the upper edge being nearly white, margined broadly with dark brown or black-brown. In females, the upper two-thirds of forewing is light ochreous or light grey-ochreous, the contrast not so pronounced between upper and lower portions in coloration, but the markings are like those of males. When wings are folded, three or four diamond-shaped areas formed by forewings are visible on the dorsal side when moth is at rest, hence the common name 'diamondback moth'. Moriuti (1986) gives details of wing venation and genitalia. The moths are weak fliers and can disperse, on average, only 13-35 m within a crop field (Mo JianHua et al., 2003). They are readily carried by the wind and can travel long distances, at 400-500 km per night (Chapman et al., 2002).
Egg

Recognition


Colour: when disturbed, tiny adults fly from plant to plant. When at rest, three or four diamond-shaped areas formed by two forewings, are visible on the dorsal surface. Pale-green larvae with pale green to brown head capsules or brown pupae covered in white silken cocoons are present on plant parts damaged by P. xylostella.
Size: adult 10-12 mm long, fully-grown larva 10 mm long, pupa 5-6 mm long.
Behaviour: adults fly when disturbed. Larvae curl up when disturbed, or drop from the foliage to the ground.
Traps: adults are attracted to light traps. Adult males are attracted to sex pheromone which consists of three chemicals: (Z)-11-hexadecenal, (Z)-11-hexadecenyl acetate and (Z)-11-hexadecenyl alcohol (Chow et al., 1978). The yellow sticky traps can also be used to monitor populations in the field (Sivapragasam and Saito, 1986).
Food: Major host plants associated with the family Cruciferae with a few host plants in the family Capparidaceae (Idris, 1998;Tanaka et al., 1999).
Scouting Techniques in Oilseed rape
The count method, although often laborious, is currently the most accurate method of estimating P. xylostella population densities in oilseed rape. It involves performing counts of larvae in several locations throughout the field and determining the average population per unit area. Remove plants in an area of 0.1 m 2, beat them onto a clean surface, and count the number of larvae dislodged from the plants. Scout at least five locations per field and monitor crops at least twice weekly (Canola Council of Canada, 2014).
The action threshold in Canadian oilseed rape crops is 20-30 larvae/0.1 m 2 at the advanced pod stage. This works out to approximately two to three larvae/plant, given the plant population is about 100 plants/m 2 (Canola Council of Canada, 2014).
Sweep net sampling and trapping (e.g. sticky, pheromone and bowl traps) can be used to detect the presence and general abundance of P. xylostella in the field, but these tools alone may not provide a reliable estimate of larval density. Nevertheless, high counts in sweep sampling and trapping can prompt growers to use the more accurate 'count method' (Sarfraz et al., 2010;Canola Council of Canada, 2014).
In regions such as Canada where P. xylostella infestations are associated with annual migrations, pheromone traps coupled with wind trajectory models are useful tools to determine the size and timing of the moth flight.
Scouting Technique in Brassica Vegetables
In Brassica vegetable crops, the 'percent infested' threshold scouting technique is more efficient in detecting damaging pest populations as it avoids the need to remove plants and count pests and is relatively easy for growers to use (Berry, 2000). This technique is successfully used to scout several other insect and mite pests in commercial crops.
Various types of traps (e.g. sticky, pheromone, pitfall and bowl traps) can also be used to detect the presence and relative abundance of P. xylostella in the field.

Symptons


The insect larva is a surface feeder and with its chewing mouthparts it feeds voraciously on the leaves leaving a papery epidermis intact. This type of damage gives the appearance of transluscent windows or 'shot holes' in the leaf blades. Insect larvae and, in many cases, pupae are found on the damaged leaves. In cases of severe infestation, entire leaves could be lost, leaving only the veins. The larvae nibble the chlorophyll-rich green areas of stems and pods and the damage shows from a distance as an unusual whitening of the crop. The damage is often first evident on plants growing on ridges and knolls in the field (Canola Council of Canada, 2014). Heavily damaged plants appear stunted and in most cases die.
In oilseed rape plants, larvae also feed on flower buds, flowers and young seed pods. The seeds within damaged pods do not fill completely and pods may shatter prematurely. Larvae also chew into pods and consume the developing seeds. Extensive feeding on the reproductive plant parts significantly reduces crop yields (Canola Council of Canada, 2014).

Impact

The diamondback moth (DBM) is one of the most studied insect pests in the world, yet it is among the 'leaders' of the most difficult pests to control. It was the first crop insect reported to develop resistance to microbial Bacillus thuringiensis insecticides, and has shown resistance to almost every insecticide, including the most recent groups such as diamide. DBM is a highly invasive species. It may have its origin in Europe, South Africa or East Asia, but is now present wherever its cruciferous hosts exist and is considered to be the most universally distributed Lepidoptera. It is highly migratory and wind-borne adults can travel long distances to invade crops in other regions, countries and continents. Immature stages also hitchhike on plant parts and can establish in new areas. DBM costs the global economy an estimated US$4 -5 billion annually, but its impacts on local biodiversity and habitats in exotic ranges are unknown.

Hosts

The natural host plant range of P. xylostella is limited to Brassicaceae which are characterized by having glucosinolates, sulfur-containing secondary plant compounds. Glucosinolates may be toxic to generalist insects, but DBM is known to rely on some of them for host location, oviposition and herbivory. Certain glucosinolates, cardenolides, plant volatiles, waxes, as well as host plant nutritional quality, leaf morphology and leaf colour, or a combination of these factors, may trigger reproductive and feeding activities of DBM (Sarfraz et al., 2006 and references therein).
Cruciferous weeds serve as alternate hosts (Sarfraz et al., 2011). For instance, the wind-borne moths can arrive in parts of the oilseed rape growing areas in Canada from the southern USA early enough that many of the rape crops will not have emerged yet (Canola Ccouncil of Canada, 2014). In these situations cruciferous weeds become important alternate 'bridge' hosts.
Some populations have also been found to infest non-cruciferous plants (see List of Hosts). However, host plant shift from feeding on crucifers to feeding on non-crucifers may depend on geographical populations. For example, a Kenyan population of P. xylostella adapted to sugar snap peas (Löhr and Gathu, 2002) whereas a Canadian population, despite of multiple attempts, could not survive on peas in the laboratory (Sarfraz, unpublished data).
For further information on hosts, see Sarfraz et al. (2006, 2010, 2011) and references therein, and Sakakibara and Takashino (2004).


Source: cabi.org
Description


The following description is taken from Flora of China Editorial Committee (2015):
C. viscosa is an annual herb, up to 160 cm tall. Stems simple or branched, ± glandular hirsute, viscous. Petiole 1.5–4.5(–8) cm, glandular hirsute;leaflets 3 or 5;leaflet blades ovate to oblanceolate-elliptic, (0.6–)2–6 × 0.5–3.5 cm, both surfaces glandular hirsute, margin entire to glandular ciliate, apex acute to obtuse. Inflorescences 5–10 cm but 10–15 cm in fruit;bracts 1–2.5 cm, palmately compound, 3-foliolate, often deciduous, glandular hirsute. Pedicel 0.6–3 cm, glandular hirsute. Inflorescences 3–6-flowered. Sepals green, equal, distinct, 5–10 × 0.8–1.2 mm, lanceolate, persistent, glandular hirsute, base cuneate, margin entire. Petals bright yellow, basally sometimes purple, arranged in an adaxial semicircle before anthesis but radially arranged at anthesis, 7–14 × 3–4 mm, oblong to ovate, clawed. Stamens (dimorphic, 4–10 adaxial ones much shorter with a swelling below anthers) green, 5–9 mm;anthers green, 1.4–3 mm. Pistil 6–10 mm, densely glandular;style 1–1.2 mm;stigma capitate. Fruit capsule 3–10 cm × 2–4 mm, strongly ridged longitudinally, dehiscing only partway from apex to base, glandular pubescent or essentially glabrous. Seeds 25–40 (up to 100) per capsule, light brown, 1.2–1.8 × 1–1.2 mm, compressed spherical, transversely finely ridged.

Impact

C. viscosa is a fast-growing herb of humid and warm habitats. It is commonly found growing as a weed in disturbed sites, gardens, rice paddies, pastures, orchards, abandoned lands, and along roadsides (Flora of China Editorial Committee, 2015;PROTA, 2015). This species is included in the Global Compendium of Weeds where it is listed as an environmental and agricultural weed with moderate economic impacts principally in rice paddies and sugarcane plantations (Randall, 2012). It produces large numbers of sticky seeds which can be dispersed by wind, water, and as a contaminant in farm machinery, farm produce, soil, or adhered to clothes and animal fur (Smith, 1981;PROTA, 2015). Currently, C. viscosa is listed as invasive in India, Singapore, Dominican Republic, Puerto Rico, the Virgin Islands, Galapagos Islands, and on several islands in the Pacific Ocean such Fiji, French Polynesia, Guam, and Papua New Guinea among others (Waterhouse, 1993;Kairo et al., 2003;Chandra, 2012;PIER, 2015;Rojas-Sandoval and Acevedo-Rodriguez, 2015).

Hosts

C. viscosa is a weed in ruderal areas, woodland, grassland, rice paddies, and sugarcane plantations (Holm et al., 1979;Flora of China Editorial Committee, 2015;PROTA, 2015).


Source: cabi.org
Description


Annual, with fibrous, rather shallow roots. Culms stout, usually reddish-purple, erect, ascending or decumbent, often branching from the base, often rooting at the lower nodes, 20-60 cm tall, sometimes nodes conspicuously swollen and usually geniculate, compressed, lower internodes often exposed. Sheath 3-7 cm long, compressed, keeled, glabrous, ligule absent;leaf blades light green, sometimes with transverse purple bands, flat, glabrous, elongate, 4-10 cm long, 3-8 mm wide, margins occasionally scabrous, apex acute. Panicle erect or nodding, green or purple-tinged, 5-15 cm long. Racemes numerous, 2-4 cm long, spreading, ascending, sometimes branched, the lower ones up to 1 cm apart, the upper ones crowded.
Spikelets green tinged with purple, crowded, arranged in ca 4 rows, about 3 mm long, rarely with a short point up to 1 mm long. First glume, 1.2-1.5 mm long, 3-nerved, nearly half as long as the spikelet;second glume, 2.5-3 mm long, 7-nerved;the first lemma is similar to the second glume, first palea ovate, ca 2 mm long, glabrous;second lemma, broadly ovate, ca 2 mm long, glossy. Caryopsis whitish, broadly ovate, 1.7- 2 mm long, flat on one side, convex on the other (Wagner et al., 1999).
E. colona is smaller, branches more at the base and has a more spreading or open type of growth than E. crus-galli (Williams, 1956a).
Seedlings have rolled leaves with pointed tips. The blades and sheaths are usually, but not always, green. There are no auricles or ligules and stems are circular in cross-section. The lowermost leaf sheath has a few hairs but most other leaf sheaths are smooth. The usually flaccid leaf blade has faint striations, a white midrib and smooth margins, at least in the upper part. Young plants have erect leaves thickened at the base and culms are sometimes flat and spreading (Zimdahl et al., 1989).
The absence of a ligule, the purplish-tinged leaves and the neatly 4-rowed racemes are characteristic of E. colona.

Impact

E. colona is a cosmopolitan weed common in crops (mainly rice, maize and vegetables), gardens, roadsides, disturbed sites, waste areas and pastures. It also grows along waterways, on the margins of lakes and ponds, in swamps and wetlands, and in other damp habitats. It has the potential to invade natural areas and completely outcompete native vegetation. In Australia, the USA, South and Central America, it is ranked among the top environmental weeds (USDA-NRCS, 2014). In Australia, this species has invaded wetter habitats, including endangered swamp tea tree (Melaleuca tamariscina subsp. irbyana) thickets (Queensland Department of Primary Industries and Fisheries, 2011).


Source: cabi.org
Description

E. fosbergii is an annual, erect or ascending herb, branched, 20 to 50 cm (up to 100 cm) tall. Stems glabrous to sparsely pilose or sometimes prominently villous-pilose near the axils of the middle cauline leaves. Leaves alternate, broadly ovate to oblanceolate, often tapering to a prominently winged petiole and therefore appearing pandurate, the base sessile to auriculate, the margin weakly serrate to dentate or sometimes lobed, the teeth callose-tipped, overall 5-10 cm long, 2-5 cm wide, about 2 times longer than wide, the uppermost leaves reduced to linear serrate clasping bracts. Inflorescence of one to several headed, loose, corymbiform cymes arising terminally or laterally in the axils of the upper cauline leaves. Heads turbinate or sometimes weakly urceolate or becoming weakly campanulate in age, robust, 2-3 times longer than wide, the florets prominently exserted approximately 2 mm beyond the involucre;involucral bracts 8-13, linear, (7-) 9-12 mm long;receptacle flat to convex, the carpopodia forming prominent tubercles after achenes have been shed;florets 15-30, varying greatly in size with the robustness of the plant, the corollas pink to light purple or red but not orange. Achene reddish brown to light tan, columnar, approximately 5 mm long with a row of strigose-hirsute pubescence on each of the 5 prominent ribs;pappus of abundant, white, capillary hairs (Flora of Taiwan Editorial Committee, 2014;Missouri Botanical Garden, 2014).

Impact

E. fosbergii is a cosmopolitan annual herb included in the Global Compendium of Weeds (Randall, 2012). It is fast-growing, with the capacity to grow as a weed and colonize disturbed areas, waste ground, gardens, abandoned farmland, coastal forests, forest edges, pastures, roadsides, rocky areas, and riverbanks (Wagner et al., 1999;Vibrans, 2011;Pruski 2014). It produces large amounts of wind-dispersed seeds (5000 seeds per plant;Mejía et al., 1994) which is a feature facilitating the likelihood of spreading and colonizing new habitats. Currently, E. fosbergii is listed as invasive in Mexico, Central America, West Indies, and on several islands in the Pacific Ocean (see Distribution Table for details).

Hosts

E. fosbergii has been listed as a weed in rice plantations in Colombia and coffee plantations in Costa Rica. It is also listed as a weed in cassava and sugarcane plantations in Central and South America (Echegoyen-Ramos et al., 1996, Murillo et al., 2006;Vibrans, 2011).


Source: cabi.org
Description


Primarily from Clayton et al. (2014) and Cowie et al. (2000), with minor additions from Florida collections:
Habit

Recognition


Diagnostic features of the genus Hymenachne include its aquatic habit and lower internodes filled with spongy aerenchyma, the cylindrical inflorescence, the margins of the upper lemma being flat and the glumes not saccate (Webster, 1987). In Australia, the genus is ultimately characterized from other Panicae by the first glume which encircles the spikelet base (Webster, 1987).
Commodity inspectors should be wary of contamination in rice seed, especially rice grown in Central and South America or Louisiana, USA. Inspectors should look for the spikelets, which are light in colour, flattened, and only a few millimetres long;the actual seed/fruit (caryopsis) is too small to detect with the unaided eye.
A trained botanist having intact, mature spikelets may find them possible to identify using the illustration provided (see Images, above) and the following characters:
1) Lower glume wrapping the base of the spikelet and small, appearing only 1.3 as long as the spikelet and wedge shaped at the tip, 3-5 nerved and scabrous on the keel.
2) Lower lemma 3.6-4.6 mm, 5 nerved and tapering gradually to a long point, longer than the fruit, margins flat, and scabrous on the nerves.
3) Upper glume 2.8-3.9 mm long, 5 nerved and scabrous on the nerves.
Vegetative material may be less likely to be transported, but is easier to recognize. Use the illustration above to focus on:
1) Leaf blade flat with base auriculate and clasping
2) Leaf glabrous except for the base having a few long hairs
3) Stems solid
4) Nodes with adventitious, spongey roots

Impact

H. amplexicaulis is a perennial, stoloniferous, freshwater grass that forms monospecific stands in seasonally flooded environments of tropical, subtropical, and warm temperate climates. It is native to Central and South America, where populations have increased around human disturbance. H. amplexicaulis has been introduced to the USA and Australia, where both countries first observed its invasive abilities in the 1990s. Robust, long lived, tolerant to hydrological fluctuation, and able to spread locally by fragments and across distances by seed, H. amplexicaulis is capable of displacing native species and altering indigenous communities under natural regimes. It is known to hinder irrigation, drainage and hydroelectric systems in agricultural and urbanized systems. It has also corrupted indigenous genotypes by hybridizing with a native Australian congener to form the morphologically intermediate hybrid H. x calamitosa. H. amplexicaulis was ranked by the Florida Exotic Pest Plant Council as a Category I invasive due to the ecological damage it has caused. In Australia, it is prohibited as a Class 2 Declared Pest and named a Weed of National Significance for its proven potential to invade wet areas across a wide geographic range.

Biological Control
<br>An effective biological control agent has not been determined for H. amplexicaulis, although studies have been made.<br>The sap-feeding bug Ischnodemus variegatus, discovered on H. amplexicaulis in Florida, has been found to reduce the plant’s growth rate and biomass (Overholt et al., 2004). I. variegatus is predicted to complete three to five generations per year in areas where its host plant has invaded Florida (Diaz et al., 2008). Laboratory studies found that it developed and survived best on H. amplexicaulis (23.4% survival) than on other genera tested (Diaz et al., 2009) and that it performed poorly overall on H. acutigluma when compared to H. amplexicaulis (Diaz et al., 2010).<br>An undescribed Delphacidae species found naturally occurring on H. acutigluma in Australia did not occur nearby on H. amplexicaulis and did not develop on H. amplexicaulis in laboratory tests. The insect species proved to be host specific to H. acutigluma, causing yellowing and weakening of that species under high densities in the laboratory (Bell et al., 2011).

Source: cabi.org
Description

Herbaceous, twining or creeping vine, attaining 3 m or more in length. Stems cylindrical, usually reddish, with long, erect, yellowish, non-glandular hairs. Leaves alternate, 5-palmately compound;leaflets 4-14 x 2-6 cm, oblanceolate or elliptical, the apex and base acuminate, the margins entire and ciliate, hispidulous to glabrate on both surfaces. Flowers in dichasial cymes;peduncles shorter than the petioles, hairy;bracts deciduous;sepals subequal or unequal, 1.5-2 cm long, with long, yellowish hairs;corolla funnel-shaped, white, 2.5-3 cm x 4-4.5 cm;five stamens, white;stigma bilobed, white. Fruit capsular, 4-valvate, subglobose, 1-1.5 cm in diameter, light brown, glabrous, surrounded by the persistent sepals. Four seeds per fruit, obtusely triangular, 5-6 mm long, brown, glabrous (Acevedo-Rodríguez, 2005;Austin et al., 2012).

Recognition

M. aegyptia can be easily recognized in the field by the 5-digitate leaves with entire leaflets, and the long, erect hairs covering the stems and calyx.

Impact

Merremia aegyptia is an annual climbing herb that acts as a pioneer species in disturbed sites in tropical regions. It is considered a weed in most countries where it occurs and it has been included in the Global Compendium of Weeds as an agricultural and environmental weed (Randall, 2012). The species is native to tropical America and Africa and listed as invasive in Cuba, India, Australia and Hawaii.

Hosts

M. aegyptia is a relatively common weed in sugarcane (Brazil, Lesser Antilles, Reunion) and maize fields (Guatemala, Brazil, Nigeria), where it climbs up plants, bending and entangling their stems (Standley and Williams, 1970;Fournet and Hammerton, 1991;Lima e Silva et al., 2004;Valery, 2006;Chikoye et al., 2009;Correia et al., 2010;Correia, 2016). It has also been reported in cotton (Cardoso et al., 2010), banana (Isaac et al., 2009), rice (Ismaila et al., 2015), green pepper (Coelho et al., 2013), muskmelon (Teófilo et al., 2012), yam (Fournet and Hammerton, 1991) and coffee plantations (Gavilanes et al., 1988).


Source: cabi.org
Description

P. foetida is a branched annual or perennial herbaceous vine 1-5 m tall with an annual or perennial woody tap root. Most parts of the above ground plant carry distinctive glandular hairs, the tips of which secrete a distinctively odorous substance. The plant scrambles or climbs by means of tendrils, and spreads only by seed.
Stems 1-5 m long, branched, herbaceous, round, green and finely hairy.
Leaves single, alternate, stipules to 1 cm long and divided into hair-like segments, petiole 2-10 cm long without nectary glands, blades 5-15 cm long, 3 or 5 lobed, the base cordate, the edges generally fringed with glandular hairs, the veins prominent, pale green and often finely hairy.
Tendrils leaf-opposed, unbranched, coiling and grasping.
Flowers solitary in upper leaf axils, peduncle 3-5 cm long, bracts 2-4 cm long and deeply divided into hair-like segments that surround the flower and fruit, sepals 5, greenish petals 5, blunt, white to pale purple or pinkish, 3-5 cm across surrounding a 2-rowed corona of purplish filaments, 5 stamens spreading at the top of a column, styles 3.
Fruits oval, 2-3 cm long, smooth, enclosed in hairy bracts. At first fleshy and green, maturing dry and yellow or orange to red, sometimes spotted, even pale green (Amela Garcia, unpublished data).
Ripe seeds blackish, flattened, wedge-shaped, 3-4 mm long, irregularly ridged, surrounded by a transparent aril.
Seedlings with epigeal germination. Hypocotyl 8-12 mm long, hairless, light green. Cotyledons shortly stalked, oblong, light green, 8-12 mm long, hairless, strongly veined. Juvenile leaves single, ovate, irregularly lobed, 12-14 mm long, with glandular hairs on margins and stalks. Seedlings foetid when crushed.

Impact

The following summary is from Witt and Luke (2017)

Hosts

P. foetida occurs in a very wide range of crops, pastures and plantations.


Source: cabi.org
Description

Phytoplasmas were originally referred to as mycoplasma-like organisms (MLOs) since morphologically and ultrastructurally they resemble the true mycoplasmas (Mycoplasma spp.), which belong to the class Mollicutes of the kingdom Prokaryotae. Ultrastructural studies of ‘ Ca. Phytoplasma australiense’ have been performed by several researchers (Ushiyama et al., 1969;Magarey et al., 1988;Andersen et al., 2001;Beever et al., 2004). The phytoplasmas were reported to be pleomorphic, comprising round, elongate, dumbbell and ring shaped elements, mostly 150 to 250 nm across but extending in length to 1000 nm and characterized by a peripheral zone of ribosome-like granules around a central nucleoplasmic net (Andersen et al., 2001). Although phytoplasmas cannot be morphologically or ultrastructurally distinguished from one another using electron or light microscopy (McCoy, 1979), it is a useful tool to confirm the presence of phytoplasmas detected by molecular methods.

Recognition

In some cases, disease symptoms associated with ' Ca. Phytoplasma australiense' can be quite definite, such as cabbage tree in late stages of infection. In other hosts for reliable diagnosis, phytoplasma infection of plants showing symptoms need to be confirmed by PCR, because the symptoms can bear similarities to those caused by other factors.

Symptons

Symptoms associated with AGY phytoplasma infection of white grape varieties include irregular chlorosis or yellowing of leaves, which is seen as reddening in red varieties. The chlorotic patches on affected leaves may become necrotic. Leaves of affected shoots can overlap one another. Inflorescence/bunches may die. Berries of more developed bunches shrivel and fail to ripen. Stems of affected shoots often take on a bluish hue. Only a few shoots on a grapevine are usually affected and inflorescence and fruit are generally only affected on symptomatic shoots. Later in the season affected shoots tend to remain green and rubbery. In some situations phytoplasma infections may be associated with restricted growth of the grapevine but the nature of this association is not well understood. In Australia, infected grapes may not display symptoms every season (Constable et al., 2003, 2004)
Symptoms on pawpaw induced by PDB phytoplasma infection include: bunching of the inner crown leaves, rapid chlorosis of recently matured leaves, bending of the growing point, reduced latex flow, abnormal ripening or abscission of the fruit and death of the crown within one to four weeks of the first visible symptoms (White et al., 1997).
Other hosts in Australia may exhibit symptoms of leaf yellowing and curling in pumpkin, patchy chlorosis of the crown, dieback of apical and lateral branches and small leaves showing tip necrosis in sweet gum, witches'-broom, interveinal chlorosis and stunted growth in paulownia and little leaf and yellowing in bidgee-widgee.
Symptoms on New Zealand flax (Phormium spp.) induced by PYL phytoplasma infection include: abnormal yellowing of the leaves, stunted growth, increased root death, phloem necrosis and xylem gummosis of the rhizome vascular system (Liefting et al., 1996;Andersen et al., 1998a).
Symptoms on strawberry plants with little leaf and lethal yellows disease, induced by strains of ' Ca. Phytoplasma australiense' include: stunting, purpling of older leaves, reduced leaf size, yellowing of younger leaves and occasional plant death (Andersen et al., 1998b;Constable et al., 2016).
Symptoms on cabbage tree (Cordyline spp.) start as vascular discolouration and leaf yellowing followed by leaf desiccation and eventual plant collapse resulting in rapid death of affected plants within months of the first external symptoms becoming apparent (Andersen et al., 2001).
Symptoms on coprosma include leaf reddening or bronzing and dieback of shoots and branches (Beever et al., 2004).
Other hosts in New Zealand exhibit symptoms of upward rolling and purpling of the leaves (potato), witches'-broom, foliar yellowing and reduced leaf size (Jerusalum cherry), pink coloured foliage and leaf distortion (celery) and stunting of lateral branches and production of small chlorotic leaves (boysenberry) (Liefting et al., 2011).

Impact

Phytoplasmas are wall-less, phloem-limited unculturable bacteria that are naturally spread by sap-sucking insects. ‘ Candidatus Phytoplasma australiense’, subgroup 16SrXII-B, is associated with a wide range of diseases in Australia and New Zealand. Important commercial crop hosts of ‘ Ca. Phytoplasma australiense’ include grapevine, papaya and strawberry. This phytoplasma is associated with rapid death of its papaya and cabbage tree hosts. In New Zealand, the insect vectors have been confirmed to be the endemic Cixiid planthoppers, Zeoliarus atkinsoni and Z. oppositus, while in Australia no vector has yet been determined, although the leafhopper, Orosius argentatus, has been implicated. Long distance spread of the phytoplasma is possible through infected vegetative propagating material. ‘ Ca. Phytoplasma australiense’ is on the A1 list of regulated organisms for Canada and Bahrain, and is listed as a quarantine pest for the USA.

Hosts

In Australia, important commercial crop hosts for ' Ca. Phytoplasma australiense' include grapevine (AGY phytoplasma), papaya (PDB phytoplasma) and strawberry (green petal, little leaf or lethal yellows diseases) (Padovan et al., 1998). In Australia, other plant hosts of ' Ca. Phytoplasma australiense' include: Acaena novae-zelandiae (bidgee-widgee), Carica papaya (papaya), Catharanthus roseus (periwinkle), Cucurbita maxima (pumpkin), C. moschata (pumpkin), Einardia nutans (climbing saltbush), Enchylaena tomentosa (ruby saltbush), Euphorbia terracina (false caper), Exocarpus cupressiformis (cherry ballart), Gomphocarpus fruticosa (cottonbush, swan plant), Melilotus indicus (hexham scent), Jacksonia scoparia (winged broom pea), Liquidambar styraciflua (sweetgum), Paulownia fortunei (paulownia), Phaseolus vulgaris (bean), Helminthotheca (Picris) echiodes (bristly ox tongue), Maireana brevifolia (yanga bush), Medicago sativa (alfalfa), M. polymorpha, Trifolium spp. (clover) and Vigna radiata (mung bean) (Krake et al., 1999;Schneider et al., 1999;Davis et al., 2003;Pilkington et al., 2003;Bayliss et al., 2005;Streten et al., 2005b;Streten and Gibb 2005;Magarey et al., 2006;Getachew et al., 2007;Habili et al., 2007;Constable et al., 2016;Dermastia et al., 2017). Although bidgee-widgee, pumpkin, climbing saltbush, ruby saltbush, false caper, cherry ballart, swan plant, winged broom pea, bristly ox tongue, yanga bush, clover, cottonbush and M. polymorpha have been found near commercial crops of grapevine and strawberry, it is not known if they are incidental hosts or important in the epidemiology of diseases associated with ‘ Ca. Phytoplasma australiense’.
In New Zealand, the common diseases associated with ' Ca. Phytoplasma australiense' are Phormium yellow leaf, strawberry lethal yellows, Cordyline sudden decline and Coprosma lethal decline. Since 2009, ' Ca. Phytoplasma australiense' has also been reported in Solanum tuberosum (potato), Solanum pseudocapsicum (Jerusalem cherry), Gomphocarpus fruticosa (swan plant), Apium graveolens (celery) and a Rubus hybrid (boysenberry) (Liefting et al., 2011).


Source: cabi.org
Description


The live adult female is 2.9-5.0 mm long and 2.4-4.0 mm wide, with a pale yellow oval body covered in white wax or sulfur-yellow flocculent wax tinged with white. In the slide-mounted adult female, the antennae each have 9-11 segments and there are three pairs of abdominal spiracles towards the apex of the abdomen. The center of the abdominal venter becomes invaginated to form a marsupium into which the vulva opens, and there is a marsupial band of simple multilocular pores along the lip of the marsupium, which becomes sclerotized with age.

Recognition


Foliage and stems should be inspected for lumps of white or yellow wax secreted by scale insects, symptoms of pest attack, attendent ants, sticky honeydew and sooty mould growth on leaves. A user-friendly, online tool has been produced for use at US ports-of-entry to help with the identification of potentially invasive scale insect species (Miller et al., 2014a,b).

Symptons


Most damage to plants is caused by the early immature stages of I. samarai, which feed on the leaf undersides, settling in rows along the midrib and veins, and on smaller twigs. The older nymphs feed on larger twigs, and as adults they settle on larger branches and the trunk. Damage to plants results from phloem sap depletion during feeding, leading to shoots drying up and dying. Trees that are badly attacked suffer partial defoliation and a general loss of vigour. The insects dischargesugary honeydew, which can be copious in large colonies and may foul plant surfaces. Besides direct damage by feeding, indirect damage can result from the development of black sooty mould on the honeydew on leaf surfaces, blocking light and air from the plant, leading to a reduction in photosynthesis (Beardsley, 1955).

Impact


The scale insect Icerya samaraia (formerly Steatococcus samaraius) occurs in the Australasian, Oriental and Oceanic zoogeographic regions. It has a wide host range which includes mostly woody plant species in 40 genera belonging to 25 families. It is a minor pest of citrus, banana, coconut, guava, papaya, cocoa, pigeon pea and other plants, including forest and ornamental trees. Populations of I. samaraia are apparently being kept under control on the Palau Islands in the western Pacific Ocean by natural enemies, particularly by the introduced coccinellid Rodolia pumila. I. samaraia can be transported on infested plant materials because of its small size and habit of feeding in concealed areas, making it a potential threat as an invasive species.

Hosts

I. samaraia has been reported on mostly woody plant species in 40 genera belonging to 25 families from the Australasian and Oriental zoogeographic regions (Miller et al., 2014a).

Biological Control
<br>The coccinellid predator Rodolia pumila is believed to be specific to Icerya species and closely related scale insects, and has been used successfully for the biological control of the related species Icerya aegyptiaca on some islands of Micronesia (Schreiner, 1989;Waterhouse, 1993).<br>Of three species of Rodolia (R. pumila, R. cardinalis and R. breviuscula) introduced to the oceanic Pacific for the control of I. aegyptiaca, I. purchasi and I. seychellarum, only R. pumila became widely established on the high islands of Micronesia by the 1950s. R. pumila appears to have been less successful on low coral atolls, possibly after reducing the abundance of its hosts to such low levels that the coccinellid was unsustainable (Beardsley, 1955;Schreiner, 1989;Waterhouse, 1993). This leads to a boom and bust cycle, with predatory beetles disappearing for long enough in some locations for damaging populations of I. aegyptiaca to develop for several years at a time (Waterhouse, 1993). R. pumila is also reported to keep populations of I. samaraia under control in Palau (Beardsley, 1966).<br>Another coccinellid, Cryptolaemus montrouzieri, was introduced for the control of Icerya spp. in Palau and Saipan (Northern Mariana Islands) and became established by 1940 (Schreiner, 1989;Waterhouse, 1993). It has been recorded attacking I. samaraia in Palau (Beardsley, 1955).

Source: cabi.org
Description

A. biennis is an annual or biennial herbaceous plant. Stems are 1–3 m tall (although flowering plants may be as little as a few cm tall), erect and more or less spike-like, simple or somewhat branching at the base from a firm taproot. The stems are glabrous throughout, striate and often reddish.The leaves are alternate, glabrous, sessile, pinnatifid into narrow lobes with the lower leaf segments also pinnatifid, lobes of all but the uppermost toothed. Inflorescence a compound spike-like panicle, leafy throughout, with dense clusters of more or less globose capitula (flower heads) which are nearly sessile along short branches arising from upper leaf axils. Each flower head consists of a hemispheric involucre 2–3 cm long, made of 8–14 glabrous bracts. There are 6–22 or more outer pistillate (ray) florets, and 15–40 central bisexual disc florets. Corollas very small, pale yellow to whitish, with scattered stalked glands;corollas of the outer ray flowers about 1 mm long, somewhat tubular;those of the disk flowers bell-shaped, 1–2 mm long, with five triangular teeth. Cypselae (seeds) obovoid to ellipsoid, glabrous, lacking a pappus (bristles), very small (0.2–0.9 mm long), longitudinally 4-5 nerved and light brown.

Impact


The large seed production, small sticky seeds and adaptation to disturbed habitats facilitated the early and rapid spread of A. biennis beyond its natural range in North America, along transportation corridors and in association with human activities. In recent decades it has become invasive in some agricultural areas in North America. The increasing prevalence of A. biennis in agricultural lands seems to be associated with several factors, including: a shift to annual growth habit;increasing adoption of reduced tillage systems;crop diversification;and, a tolerance to several classes of herbicides. In Europe, the plant has become a local weed, but has not yet been reported as invasive in crops. However, increased frequency has been observed in some countries and changes in land use and agricultural practices suggest the potential for emerging problems in Europe in the future.


Source: cabi.org
Description


Herbaceous vine, much branched from the base, climbs by means of tendrils and attains 1.5-2 m in length. Stems with 5 longitudinal ribs, glabrous or puberulent;cross section with a single vascular cylinder. Leaves alternate, biternate;leaflets chartaceous, puberulent or sparsely pubescent, the apex obtuse, acute, or acuminate, the base attenuate, the margins lobate or laciniate;terminal leaflet lanceolate or triangular, rhombic or narrowly lanceolate in outline, 2-3.5(5) cm long;lateral leaflets ovate, lanceolate, or oblong in outline, 1-2.5 cm long;rachis and petiole not winged;petioles 2-3 cm long;stipules lanceolate, approximately 5 mm long;tendrils in pairs, spirally twisted, at the end of short axillary axes (aborted inflorescences), from which an inflorescence usually develops. Flowers functionally unisexual, zygomorphic, in axillary racemiform thyrses, shorter than the accompanying leaf. Calyx light green, of 4 unequal sepals, the outer ones approximately 1.2 mm long, the inner ones 3-3.5 mm long. Petals white, obovate, 2.5-3.5 mm long;petaliferous appendages slightly shorter than the petals, fleshy and yellow at the apex, forming a hood that encloses the apex of the glands of the disc;disc unilateral, with 4 rounded or ovoid glands, approximately 0.4 mm long;stamens 8, the filaments unequal, pubescent;ovary trilocular, with one style and 3 stigmas. Capsules brown, pearlike, turbinate-obtriangular or sometimes nearly ellipsoid, 1.5-3 × 2-4 cm, pubescent. Seeds black, shiny, approximately 5 mm in diameter;hilum green when fresh, white when dry, cordate (Acevedo-Rodríguez, 2005;Flora of China Editorial Committee, 2015).

Impact

C. halicacabum is a long-lived scrambling, creeping, or climbing vine that is a weed of gardens, roadsides, disturbed sites and plantations. It has also the ability to climb and cover mature trees up to 8 m or more in height (Weeds of Australia, 2015). This species is often cultivated as an ornamental in gardens of tropical and subtropical regions of the world for its inflated balloon shaped fruits (Acevedo-Rodríguez, 2005;PIER, 2015;PROTA, 2015;Weeds of Australia, 2015). It has escaped from cultivation, and once naturalized it grows over native vegetation smothering trees, shrubs and understory vegetation. It is very successful invading forest margins, woodland, grassland, riverbanks, floodplains and rocky sites. Dense infestations can also impede access, increase the risk and intensity of fires and harbour pests and diseases (Invasive Species South Africa, 2015). Currently, C. halicacabum is regarded as a weed and invasive species in Australia, South Africa, Kenya, Tanzania, Uganda, French Polynesia, the Cook Islands, New Caledonia, Singapore, the USA, and Cuba (Foxcroft et al., 2003;Oviedo Prieto et al., 2012;BioNet-EAfrinet, 2015;PIER, 2015;USDA-NRCS, 2015;Weeds of Australia, 2015).

Hosts

C. halicacabum is a weed with substantial economic impacts on sugarcane and soyabean plantations (Gildenhuys et al., 2013).


Source: cabi.org
Description

Herbaceous, twining or creeping vine, attaining up to 6 m in length. Stems cylindrical, glandular- pubescent. Leaves alternate, 5-palmately compound;leaflets 1.5-7.5 x 0.7-3.5 cm, elliptical, ovate or ovate-lanceolate, the apex obtuse, the base acute or decurrent, the margins entire, undulate or dentate, glabrate or glandular-pubescent on both surfaces. Flowers in simple or double dichasial cymes;peduncles longer than the petioles;bracts persistent, linear to subulate;sepals subequal or unequal, 1-1.5 cm long, ovate to ovate-lanceolate, acuminate at the apex, glandular-pubescent;corolla funnel-shaped, white or sometimes pink, with or without a purple centre, 1.5-3 cm x 3-4 cm;stamens 5, white, sometimes with lilac anthers;stigma bilobed, white. Fruit capsular, 4-valvate, globose, 6-8 mm in diameter, light brown, glabrous, surrounded by the persistent sepals. Seeds 4 per fruit, ellipsoid, 5-6 mm long, dark brown, lanate (Acevedo-Rodríguez, 2005;Austin et al., 2012).

Impact

Merremia cissoides is a climbing weed native to tropical America that has been introduced to several Old World countries, presumably as an ornamental. It typically grows in disturbed areas and has been reported as a weed of several crops within its native range. However, it is not as widespread and common as other weedy species of Merremia. In several countries outside its native range, its occurrence has only been documented from one or few herbarium specimens. Nonetheless, the species is considered to be increasingly naturalized in the Old World tropics. It is invasive in Florida (USA) and Cuba.

Hosts

The species has been reported as a weed of sugarcane fields in Brazil (Perim et al., 2009;Correia and Kronka Júnior, 2010) and has also been reported in maize (Tavella et al., 2015), soybean (Timossi and Durigan, 2006), eucalyptus (Carbonari et al., 2010) and coffee plantations (Gavilanes et al., 1988).


Source: cabi.org
Description


Colonies in culture are usually white, pale grey or pale orange, sometimes producing strong pinkish-purple pigments. Conidiomata are usually poorly developed, with few or no setae, especially in culture. Conidiogenous cells are roughly cylindrical, sometimes borne in weak clusters, and produce conidia successively from single loci. Conidia are 8-16 x 2.5-4 µm in size, fusiform, thin-walled, aseptate and hyaline. Appressoria are few in number, 6.5-11 x 4.5-7.5 µm in size, clavate to circular and light to dark brown.
Full descriptions are given by Dyko and Mordue (1979), Sutton (1980), Baxter et al. (1983) and Gunnell and Gubler (1992).

Symptons


The spread of the disease is often so rapid that by the time symptoms are noticed, the crop is in serious danger. For strawberry, fruit and occasionally petiole rots may be noticed, with sunken, water-soaked spots enlarging to cover the whole fruit within 2-3 days, with dark-brown fruit bodies producing pink spore masses. For other crops such as anemone and celery, crown rots and leaf curl may be the principal symptoms. In pine seedlings, the developing leaves around the apical bud are affected, with small, brown lesions appearing and rapidly extending. Severe stunting is eventually caused as the uninfected tissue beneath the apex continues to develop.

Hosts


The species has a very wide host range, but is economically most important on strawberries.
C. acutatum can apparently affect almost any flowering plant, especially in warm temperate or tropical regions, although its host range needs further clarification. It has rarely been noted on other than agricultural or forestry land.


Source: cabi.org
Description


The colonies of C. formosanus contain three primary castes: the reproductives, soldiers, and workers. The majority of the nestmates are workers that are responsible for the acquisition of nutrients, i.e. cellulose in the wood. The head width of the white soft-bodied worker is approximately 1.2-1.3 mm and the body length is approximately 4-5 mm. The thorax is narrower than head width. The alates and soldiers are most useful for identification. The alates are yellowish-brown and 12-15 mm long. There are numerous small hairs on the wings of these comparatively large swarmers. The alates are attracted to lights, so they are usually found near windows, light fixtures, windowsills and spider webs, around well-lit areas. The soldiers are approximately the same size as the workers and have an orange-brown oval-shaped head, curved mandibles and a whitish body. When disturbed, the soldiers readily attack any approaching objects and may secrete a white gluey defensive secretion from the frontal gland. There are more soldiers (10-15%) in a C. formosanus colony than in a subterranean termite colony, such as Reticulitermes spp. (1-2%).

Recognition


Occasionally the foraging tubes may be observed on the wood surface or tree trunk. During the swarming season (April to June), elongated mud tubes that serve as flight exit slits may be seen. The damage by C. formosanus tends to occur in places with high moisture including the bathroom, kitchen sinks and leaky roofs. An acoustic emission device (AED) may be used to locate sites with feeding activity, but most AEDs have a limited detection range (Scheffrahn et al., 1993).

Symptons


Large colonies of C. formosanus generally live underground. When these termites invade a house aboveground, the foraging tubes of approximately 0.5-1 cm in diameter may be found connecting the soil and the infested house. In severe infestations, C. formosanus hollows out the wood leaving a paper-thin surface and the hollowed wood surface may look blistered or peeled. Another characteristic of C. formosanus is carton nest material that is made from termite faeces, chewed wood and soil. The honeycomb-like carton nests can be as large as 1-1.5 m in diameter and are usually found in structure-voids such as between walls and beneath sinks.

Impact

C. formosanus is often transported by boats and shipping containers to port cities before being carried further inland via landscape materials such as railroad ties (railway sleepers). This may explain the current C. formosanus distribution in the USA with coastal areas more densely infested than inland areas (Hochmair and Scheffrahn, 2010). Temperature and humidity are primary factors affecting the establishment of C. formosanus, and it is potentially invasive to areas of high humidity approximately 35° north and south of the equator (Su and Tamashiro, 1987). Competition from native species is another limiting factor for many exotic pests, but C. formosanus is more aggressive and is known to out-compete the endemic termites such as Reticulitermes species. Another factor that has allowed the successful establishment and spread of C. formosanus in exotic areas has been the pest control industry's heavy reliance on soil termiticide barriers for subterranean termite control since the 1950s. Numerous studies, using mark-recapture methods, have revealed that a single colony of C. formosanus might contain several million termites that forage up to 100 m in the soil (Lai, 1977;Su and Scheffrahn, 1988). These agree with the results of excavation studies for C. formosanus colonies (Ehrhorn, 1934;King and Spink, 1969). Because of the large colony size, the application of soil termiticides beneath a structure does not usually have a major impact on the overall population, and the surviving colony continues to produce alates that can further infest nearby areas. Once established, C. formosanus has never been completely eradicated from an area. The dependency of soil termiticide barriers as the primary tool for subterranean termite control is probably the main reason for the establishment and spread of C. formosanus from four isolated port cities in the 1960s in the USA to all south-eastern states by 2001.

Hosts

C. formosanus is an opportunistic feeder of any material containing cellulose. A large number of living plants are known to be attacked by C. formosanus, but it usually does not kill the plants unless the root system is significantly damaged (Lai et al., 1983;La Fage, 1987). Records show that living citrus, eucalyptus and sugar canes (Saccharum sp.) may be killed by C. formosanus, but in most cases damage occurs in the heartwood of a tree. The infested trees may be more easily blown over by high winds due to the loss of structural strength. The pest status of C. formosanus is most significant when it attacks wood products in a house such as structural lumbers, cabinets, etc. C. formosanus is also known to damage non-cellulose materials in search of food, including plastic, concrete and soft metal. Occasionally underground high-voltage power lines may be penetrated by C. formosanus, resulting in an area-wide power cut.


Source: cabi.org
Description


The following information is adapted from Puff (1991), Nelson (1996) and Wagner et al. (1999), and modified by the datasheet author using plant specimens from warm temperate (Jacono 952, FLAS) and subtropical (Howell 1285, FLAS) regions of Florida.

Recognition


Detection of P. foetida in the field or during inspection at ports of entry can easily be made based on the following features: a slender vine with opposite, oblanceolate, sometimes nearly heart-shaped, soft green leaves having a stipular tab on the stem between the petioles, the leaves producing a foul-smelling sulfurous odour when bruised, and fruits, if present, the size of a peppercorn, with a thin, brittle skin orange to brown in colour and splitting to release no more than two seeds.

Impact


A perennial vine of South-East and East Asian origin, Paederia foetida has characteristically opposite, soft and offensively smelling leaves, and produces solitary flowers and globose fruits in a ‘double scorpioid’ inflorescence. Vines trail across the ground, clamber over shrubs and twine into tree canopies to form curtains of dense vegetation that block light, provide undue weight, and offer a pathway for fire, often leading to the death of the host. P. foetida was introduced during the 19th century to the oceanic Mascarene and Hawaiian islands and later to the continental USA (Florida). It is regionally problematic in Florida where its distribution stands to expand internally and to other southern states. It is ranked by the Florida Exotic Pest Plant Council as a Category I (high impact) invasive species, invading and impacting natural areas, and is regulated as a noxious weed in both Florida and Alabama. In the Mascarene Islands it is a serious agricultural weed, and has recently become invasive in forest parks and disturbed urban sites in southern China.

Hosts

P. foetida has been and remains a principal weed of sugarcane on the island of Mauritius (Evans, 1947;Roghegouste, 1958). Changes over time in cultural practices, such as green cane trash blanketing, have favoured its more recent proliferation in sugarcane crops (Seeruttun et al., 2005). It is also well entrenched as a weed and contaminant in the Hawaiian nursery industry for ornamental foliage plants (Pemberton and Pratt, 2002).
P. foetida becomes a serious horticultural weed when it moves into lawns and yards in suburban Florida where little can be done to control it. Green, thin and pliable, its fast growing stems creep into lawn grass safely below the circulating blade of a lawn mower. The stems readily anchor themselves by rooting at the nodes that are continuously in contact with the ground. Stems can run from lawns into shrubbery, from where, after taking many twining turns around basal branches, the vines twist their way to the top of bushes and hedges, blanketing their surfaces and moving onwards to find the next vertical support.

Biological Control
<br>A 2010 survey in Thailand and Laos found insect herbivores associated with P. foetida and three other Paederia species. A leaf-tying moth, two hawk moths, a herbivorous rove beetle, a chrysomelid leaf beetle, a sharpshooter leafhopper and a leaf-sucking lace bug were the most damaging. The beetles were being investigated by the Hawaii Department of Agriculture as potential candidates for biological control of P. foetida in Hawaii (Ramadan et al., 2011). The survey included pathogens which were found in northern Thailand and were similarly taken to Hawaii for testing. One particular isolate of the fungus Colletotrichum gloeosporioides proved to be aggressive on P. foetida and, along with other fungi, is also under investigation for biocontrol purposes (Ko et al., 2011).<br>Many of the natural enemies of P. foetida so far identified and tested as potential biocontrol agents have been rejected as not having the required level of host specificity for safe use. For example, testing of Trachyaphthona nigrita and T. sordida in their native Japan indicated that they had Paederieae tribe-level feeding specificity and so were suitable as biological control agents (Okamoto et al., 2008), but when tested under quarantine conditions in Florida, USA, they showed significant feeding on native plant species of the tribe Spermacoceae. These flea beetles, therefore, lacked the appropriate level of host specificity (Pemberton and Witkus, 2011). Testing of Dulinius conchatus in Hawaii also showed lack of skunkvine specificity (Pemberton et al., 2005). In 2013 an Asian sawfly, Formosempria varipes, was discovered feeding on P. foetida in Hong Kong. Host preference trials undertaken in Florida showed, however, that several species of Paederia could serve as host plants, thus making it unsuitable for release as a biological control agent for P. foetida in that state (Smith et al., 2014).<br>In contrast, Ko et al. (2011) report that Endophyllum paederiae [ Puccinia paederiae ], a gall rust from Thailand infecting P. pilifera, would not accept P. foetida as a host in testing, apparently having too narrow a host range.

Source: cabi.org
Description


Live adult females are oval, grey, and coated with white mealy wax which forms small tufts (Beardsley 1959). They are 1.5 mm long and 1.0 mm wide. Authoritative identification requires slide-mounted adult females under a compound light microscope. See Beardsley (1959) for a detailed description of the D. neobrevipes.

Recognition

D. neobrevipes crawlers (first-instar nymphs) can be detected in the field using blue sticky traps. Jahn and Beardsley (2000) found blue sticky traps better for trapping D. neobrevipes than yellow sticky traps, which attract high numbers of other insects, such as flies.
D. neobrevipes is only found on the aerial parts of the plant (Beardsley 1960) and is usually seen on the surface, but can feed deep in the leaf axils or within the blossom cups. Therefore, a plant may need to be dissected in order to find all of the mealybugs on it (Jahn et al., 2003).

Symptons

D. neobrevipes is usually found near the top of the host plant and feeds by sucking phloem sap from the plant tissue. This may cause local lesions to form at the site of feeding on some hosts. These lesions are bizonate, with a dark green centre surrounded by a lighter green area (Dasgupta, 1988). D. neobrevipes also affects the plant’s photosyntheitic ability by excreting sugary honeydew that fouls plant surfaces, forming a medium for the growth of sooty mould, which blocks sunlight and air from reaching the leaves, impairing photosynthesis (Tabata and Ichiki, 2015).
The main damage that pineapple mealybugs such as D. neobrevipes cause is as a result of their role as a vector of pineapple wilt. This devastating disease is caused by Pineapple mealybug wilt associated virus-2 (PMWaV-2), a mealybug-transmitted ampelovirus (Subere et al., 2011). There are two types of wilt, quick wilt and slow wilt. Quick wilt, also known as mealybug wilt, develops around 2 months after a short attack by a large colony of mealybugs, whereas slow wilt is caused by many mealybugs feeding on the plant tissue over many months (Jahn et al., 2003). Slow wilt causes the inner leaves to turn dry and brown, and outer leaves to lose their turgidity and droop (Jahn et al., 2003). Unlike slow wilt, quick wilt causes leaves to turn a light-green to yellow-pink colour in plants younger than 6 months. In older plants, quick wilt causes leaves to droop, turn pink and dry out (Carter, 1932).
Both types of wilt cause leaves to droop and dry out. They also both affect the fruit yield of the plant, especially if symptoms are seen early in the season. Affected plants either produce smaller fruit or produce no fruit at all. Pineapple wilt may also result in the invasion of saprophytic organisms, which leads to collapse of the roots (Kessing and Mau, 1992). Ultimately, plants may die as a result of infection by pineapple wilt transmitted by D. neobrevipes.
D. neobrevipes also causes green spot disease of pineapple, which is characterized by galls on leaves caused by a reaction between the plant and a secretion from the mealybugs.

Impact

Dysmicoccus neobrevipes is a mealybug with a pantropical distribution. It is an economically important pest that can feed on and damage dozens of hosts, principally pineapple and the banana Musa × paradisiaca. The main damage caused by D. neobrevipes is due to its role as a vector of mealybug wilt (Plant Health Australia, 2013). Qin et al. (2010) considered it a dangerous alien species with a high risk of invasion in China. Although D. neobrevipes can colonize without the help of associated caretaker ants, most commonly Pheidole and Solenopsis, the ants’ presence can help them to invade new areas by providing shelter and protecting them from natural enemies and adverse weather conditions.

Biological Control
D. neobrevipes has a range of natural enemies that, in the absence of caretaker ants, can effectively control populations of the mealybug. New predators can be introduced to an area in order to control the mealybugs, but without first controlling ant populations, these introductions will not be effective (Rohrbach et al. 1988).

Source: cabi.org
Description

From Takikawa et al. (1989).;P. syringae pv. actinidiae is a Gram-negative, obligate aerobe, non-sporing rod. It occurs singly or in pairs or short chains and is motile by 1-3 polar flagella. Poly-§-hydroxybutyrate granules are not accumulated.;Colonies on nutrient agar are translucent-white, slightly raised, glistening, and round. At 27¡C colonies do not exceed 1 mm after 48 hours. On King's medium B, colonies are translucent and non-fluorescent under UV light, though Cunty et al. (2014) report some strains of Psa as being fluorescent. Growth factors are not required. The pathogen is in Group Ia of the LOPAT determinative scheme of Lelliott et al. (1966) being positive for levan production and the capacity to produce a hypersensitivity reaction in tobacco, and negative in tests for oxidase and arginine dihydrolase production and pectolytic activity.

Symptons

Canes;In spring, extending canes can become water-soaked and exude a pale, translucent to dark reddish coloured ooze from lenticels of apparently healthy tissue. Small (1-3 mm) cracks form above olive-coloured, water-soaked lesions and exude gum. Lesions elongate and whole canes become necrotic.;Leaves;In spring, small, water-soaked spots form on expanding leaves. These become brown and angular with bright, chlorotic halos. On lower surfaces, translucent gum may exude from stomata.;Flowers;Most infected floral buds become brown and wither without opening. They may exude translucent gum. Sepals can become infected. Heavy flower buds may drop.;Trunks and leaders;Symptoms of canker are first observed in mid-winter when small droplets of ooze are produced. In late winter ooze increases in quantity and becomes reddish brown. When vines break dormancy, canker symptoms are revealed by gum exudation from natural openings, from cracks in the bark, and from pruning cuts. Bark in these areas is dark and dissection reveals that necrosis extends in underlying tissue beyond the externally visible discoloration. Trunks and leaders may be girdled. Prolific suckering occurs below girdling cankers (Serizawa et al., 1989, Balestra et al., 2009).


Source: cabi.org
Description

Passos de Carvalho (1994) provides many photographs of A. floccosus in Madeira.
Eggs
Eggs are very small, less than 0.2 mm in length. Usually eggs are laid in circles or semicircles. In this manner it is easier to detect the egg stages which are usually also accompanied by an area of waxy dust.
Nymphs
A. floccosus goes through four nymphal instars, the last of which becomes the pupal stage. The nymphal stages are very similar to each other and differ mainly in size. Nymphs secrete a woolly covering of rather dirty-looking, flocculent white wax. Under the wax covering, the nymphs may be pale yellow or, in some populations, brown (see comments under Taxonomy and Nomenclature).
Pupae
The puparium is the most important stage for identification. It is elongate in form, usually of a light-cream colour, but very rarely black individuals can also be found. The length varies from 0.8 to 0.92 mm and the width is 0.55-0.65 mm. Patti and Rapisarda (1981) described the pupa of A. floccosus in detail.
Adults
As with most whitefly species, adults are not used for identification, only pupal cases being used for such a purpose. Adult whiteflies are usually white, always winged, with waxy secretions on their bodies, offering few diagnostic features for identification purposes. Passos de Carvalho (1994) provides photographs of adult morphology.


Source: cabi.org
Description

C. intersecta has a small to medium shell with 5 to 6 whorls (up to 14 mm), sub-globose to turbinate, rounded domed spire, tightly coiled, solid with descending, ovate-lunate aperture and wide umbilicus. The lower lip is reflected. Sculpture of coarse radial wrinkles and lines present. The colour is buff to light brown with dark brown to black irregular blotches (Smith and Kershaw, 1979). The description from Shea (2007) reports a narrow umbilicus with rounded whorls in adults, moderately impressed sutures, thickened ring inside aperture, sculpture of radial growth line. Shell is yellowish with spirally arranged brown broken bands and flammulations and cream radial streaks.

Recognition


Some species of Mediterranean origin such as Candidula favour calcareous grasslands and sand dunes. These habitats should be checked first for accidental introductions.
In the USA, C. intersecta has been intercepted repeatedly on Italian, Spanish, Chilean and Colombian terracotta tiles, and granite, and travertine from Spain (Hitchcox, 2007;Meissner et al., 2009).

Impact

C. intersecta can be invasive in its countries of origin and is considered an agricultural pest in Europe where it can feed on cereal and horticultural crops (some pome and stone fruit) and is responsible for yield losses. Even if its economic and environmental impact has not been determined, it has the potential to cause damage in the USA, New Zealand and Australia, where it is listed as an “A pest” of quarantine concern in the Plant Quarantine Act 1997.

Hosts

C. intersecta is considered to be a potential agricultural pest. Sternberg (2000) reports that C. intersecta feeds on leaves of young annual seedlings and tissues of forbs and legumes. In Europe, Candidula snails are known to feed on apples, pears, plums and peaches, damaging unripe and forming fruit on the tree. Once damaged, fruit succumb to fungal, bacterial and yeast attack and rot before maturity. C. intersecta also feed on seeds, seedlings and young plants of spring cereals (Godan, 1983).


Source: cabi.org
Description


Colonies on potato dextrose agar (PDA) grow to 50-60 mm diameter after 6 days at 22°C under 12 h light/12 h dark cycle. Colony margin even, sporogenous tissue slightly elevated above the colony surface, 1-2 mm, buff/pale luteous. Stromatal initials forming 10-12 days after culture initiation;mature black stromatal plates at first discrete, later coalescing. Macroconidia globose, ovoid or limoniform, smooth, 12-21 x 8-12 µm, mean = 16.4 x 10.1 µm in distilled water when grown on cherry agar (CHA) at 22° under NUV;11 x 20 x 8-11 µm, mean 14.9 x 9.1 µm, on pear fruit at 15°C. Thick hyphal layer of stroma on colonized fruit;conidial tufts buff to brownish-grey.

Symptons

M. polystroma causes the same or very similar symptoms to those reported for Monilinia fructigena and, therefore, is likely to be associated with blossom, twig and leaf blights, stem cankers and brown fruit rots (Byrde and Willets, 1977). For further information on symptoms, refer to the datasheet on M. fructigena.

Impact

M. polystroma is the conidial form of an unknown apothecial ascomycete closely related to Monilinia fructigena, from which it has so far been distinguished by molecular means. Although M. fructigena and the other brown-rot species, M. fructicola and M. laxa, are known on various continents, M. polystroma was identified in Japan and initially known only in that country. Recent published reports placed it in Hungary and China as well. This species may be widely distributed in Asia and perhaps Europe. In the absence of natural barriers, it will spread by means of airborne conidia. Long distance dispersal would most likely occur through infected planting stock or fruit. Therefore, M. polystroma is a regulated pest for Canada. Monilinia fructigena is a regulated pest for the USA.

Hosts


The type description by van Leeuwen et al. (2002) only dealt with isolates from apple (Malus pumila), and a recent discovery of the species in Hungary (Petróczy and Palkovics, 2009) was also on apple. Detailed studies on the potential host range of this species have not yet been conducted. However, according to previous work carried out on Japanese isolates, then identified as Monilinia fructigena (Harada, 1998), the fungus has a host range similar to M. fructigena in Europe, and is found on species of Cydonia, Malus, Prunus, and Pyrus.


Source: cabi.org
Description

L. dalmatica is a robust, glaucous, herbaceous perennial with taproots enlarged above, more or less woody, deeply penetrating (1.8 m or more into the ground), spreading by horizontal roots 5–20 cm below the surface, spreading up to 3.6 m from the plant. Adventitious offshoots from these roots are generally sterile, decumbent to weakly ascending, succulent, 3–40 per crown. Stems from the main crown are annual, 40–100 cm high, ascending to erect, more or less woody near the ground. Leaves are alternate, often in two’s or three’s on lower part of the stem, sessile, reflexed to ascending, entire, acute to acuminate at the tip, obtuse to cordate at the base, sometimes concave above, usually amplexicaul, somewhat leathery, glabrous and sometimes rugose, with 3–7 longitudinal veins on lower surface. The lower leaves are 1-5 cm long, up to 1 cm wide, linear to lanceolate;the upper leaves 3–6 cm long, 1-4 cm wide, lanceolate to very broad-ovate. Bracts are similar to upper leaves, or smaller. Flowers are in erect or nodding, simple racemes, usually loose, sometimes compact;15–55 cm long on pedicels 1–8 mm long. Five sepals, valvate or somewhat imbricate, erect, lanceolate acute to acuminate, 0.7–1.1 cm long, 0.2–0.4 cm wide, margins entire to somewhat undulate. The corolla, including spur 3.3–4.5 cm long, light yellow to yellow, rarely nearly white;tube 6–9 mm long, the upper lip bilobate, often somewhat helmet-shaped, the lower lip trilobate;spur tapered, 1.2–1.8 cm long, straight or slightly curved;four fertile stamens adnate in pairs, didynamous 0.8–1.5 cm long, one reduced staminode;pistil bicarpellate;ovary bilaterally symmetrical ca. 2 mm diameter at anthesis, abruptly narrowed to the terminal style;style filiform, erect, stigma single, terminal, hemispherical;numerous ovules in each locule;capsule long ovoid to nearly spherical, 4–10 mm long, 4–8 mm in diameter, dehiscing terminally on each carpel. Seeds black to purplish-brown, triquetrous or somewhat compressed, muricate-rugose on the surface, 0.7–1.3 mm wide, 30–170 per locule;each seed with narrow wing on the angles. The species is morphologically highly variable (this description simplified from Vujnovic and Wein, 2005, based on original by Alex, 1962).

Impact

L. dalmatica is a herbaceous plant native to western Asia and south east Europe. It is of particular concern in North America where it was introduced in the late nineteenth century. It has since spread across most of the western areas of the USA and Canada (De Clerck-Floate and Turner, 2013). There it has invaded rangelands, rights-of-way and natural habitats. It is classified as noxious in many of the western states of both countries. It is also classed as invasive in South Africa. Its success may be attributed to its high specific leaf area, aggressive root system, prolific seed production and the presence of alkaloids which discourages grazing by livestock, thus allowing it to become dominant (De Clerck-Floate and Turner, 2013).

Hosts


The crops affected by L. dalmatica are mainly pasture and rangeland species, but alfalfa (Medicago sativa) and forest species such as ponderosa pine (Pinus ponderosa) may also be affected.

Biological Control
L. dalmatica has been the subject of a number of biological control programmes. According to De Clerck-Floate and Turner (2013), five insect biocontrol agents have been tested and intentionally introduced into Canada for control of L. dalmatica. The first field release took place in 1963.<br>Of the five insects released, three have established on L. dalmatica. These include the seed capsule weevil Rhinusa antirrhini, the defoliating moth Calophasia lunula and the stem boring weevil Mecinus janthiniformis. The latter had previously been referred to as ‘ M. janthinus ’ but differing results from different populations of this ‘species’ led to the realisation that two species were involved. Only M. janthiniformis is effective on this L. dalmatica while L. janthinus is effective on L. vulgaris (Toševski et al., 2011). Toševski et al. (2013) have now described a fast and accurate way of distinguishing the two Mecinus species haplotypes using PCR-RFLP diagnostic assay of the mitochondrial cytochrome oxidase subunit II (COII) gene.<br>R. antirrhini has established well in British Colombia, Canada and populations are increasing. It is however uncertain whether this seed feeding agent can have a significant impact on the weed (De Clerck-Floate and Turner, 2013).<br>In Canada, Calophasia lunula has only become established in southern British Colombia and not at all in Alberta, apparently due to low temperatures (De Clerck-Floate and Turner, 2013). Jamieson et al. (2010) found that C. lunula has a mechanism to de-activate the iridoid glycosides, defence mechanisms, in L. dalmatica but ‘ M. janthinus’ does not.<br>M. janthiniformis is by far the most successful biocontrol agent released in Canada. Damage is caused by both adults and larvae and conspicuous reductions in the weed have been recorded. Results are less successful in Alberta almost certainly due to severe winter temperatures. Some disappointing results may also be due to the wrong Mecinus species being released. Weed and Schwarzländer (2014) suggest that the impact of M. janthiniformis may vary considerably due to site specific variation in rainfall and density dependent processes. As a result alternative control methods should be prioritized in areas where herbivore impact is expected to be low. Studies have recently started on two additional Mecinus species, M. laeviceps and M. peterharrisi (Toševski et al., 2016). A petition for the introduction of the stem-galling weevil R. rara n North America is pending.<br>Two species introduced but not proving successful are the root galling weevil R. linariae which proved to have a preference for L. vulgaris and is no longer being exploited and the root moth Eteobalea intermediella which established in 1998 but had died out by 2002 and is no longer being used (De Clerck-Floate and Turner., 2013). The related E. serratella was thought by Quarles (2007) to be having an impact on L. dalmatica, but Shelton (2015) notes that L. dalmatica is a relatively poor host for this species and it appears that it is no longer of interest.<br>Grubb et al. (2002) suggested that the naturally occurring flower feeding beetle Brachypterolus pulicarius might prove to be an important component in the integrated weed management of L. dalmatica but that the adults show a distinct preference for L. vulgaris and its further distribution in North America was not recommended (MacKinnon et al., 2007). The seed capsule weevil R. neta also occurs widely in British Colombia, Canada but is not being actively distributed (De Clerck-Floate and Turner 2013).<br>Wilson et al. (2005) provide extremely detailed and valuable information on the biology of the biocontrol organisms and the planning, implementation and monitoring of biological control programmes against both L. dalmatica and L. vulgaris.

Source: cabi.org
Description


The genus Calacarus is a distinctive group of mites, as the females usually have a purplish body and three or five longitudinal wax-bearing ridges on the opisthosoma (Lindquist et al., 1996;Anon., 2014). Wax may also occur on the dorsal shield, following the dorsal shield lines (Lindquist et al., 1996). The rostrum of the female is relatively large and curves downwards (Huang, 2014). The coverflap of the female mite is 32.2 to 36 µ wide and 19.8 to 21.3 µ long, with many faint, short lines (Huang, 2014).

Recognition

C. carinatus causes a bronzing or purple discolouration of infested leaves (Mamikonyan, 1935;Anon., 2014). Infested leaves also have a ‘dusty’ appearance due to the cast skins of the mites and the residue of ‘mite wax’ on the leaf surface (Anon., 2014). The white skins and wax on the upper leaf surface can be seen using a hand lens (Anon., 2014). Leaves attacked by the mites turn completely brown and dry up, and defoliation occurs in heavy infestations (Shiao, 1976;Vazquez, 1991).

Symptons

C. carinatus causes a bronzing or purple discolouration of infested leaves, hence the common name ‘rust mite’ (Mamikonyan, 1935;Anon., 2014). This is more apparent on the leaf margins (Shiao, 1976). Infested leaves also have a ‘dusty’ appearance due to the cast skins of the mites and the residue of ‘mite wax’ on the leaf surface (Anon., 2014). Leaves attacked by the mites turn completely brown and dry up, and defoliation occurs in heavy infestations (Shiao, 1976;Vazquez, 1991). The mites usually attack older leaves and show a preference for the upper surface, especially along the midrib and margins (Light, 1927).

Impact

C. carinatus is a mite native to Asia. It is now also present in Africa, Europe, the USA and Australia. It usually attacks camellias and can reduce tea leaf production. In Kenya, C. carinatus has resulted in loss of capital due to the reduction in tea leaf production.

Hosts

C. carinatus usually attacks camellias, but has also been found attacking Spathiphyllum plants in Florida greenhouses (Anon., 2014). It is said to have an unusually wide host range compared to other members of the genus, apart from Calacarus citrifolii (Lindquist et al., 1996). In addition to attacking Camellia sinensis, it has also been reported from Camellia japonica and ‘two hosts in two other dicot families’ (Lindquist et al., 1996). Other hosts include: leaves of Viburnum opulus in California, USA;Capsicum annum in Mauritius (Moutia, 1958);and Camellia kissi and Camellia caudate in Assam, India (Das and Sengupta, 1962).

Biological Control
Sharma and Kashyap (2002) reported that Syrphus sp., Coccinella septempunctata, Oxyopes sp. and the parasitoid Diaeretiella sp. are the most important natural enemies in tea orchards in general in Himachal Pradesh, India, where C. carinatus is one of the most important pests attacking tea bushes. The authors investigated the effect of pesticides on pests and natural enemies and found that deltamethrin, cypermethrin and ethion were highly toxic to Syrphis sp. and C. septempunctata. Conversely, applications of 1500 ppm azadirachtin or a combination of neem, triterpenoids and azadirachtin, or Bacillus thuringiensis were found to be safe to natural enemies.

Source: cabi.org
Description

Eggs
The freshly laid egg is pale whitish-blue, translucent, and shiny. Just prior to hatching it becomes bluish-green to turquoise. It is oval-spheroid with parallel sides, blunt rounded ends, and a slightly convex ventral margin. When first deposited, the dimensions are approximately 0.4 x 1.4 mm and 0.5 x 1.7 mm just before hatching. The eggs are laid serially in slits cut in the edge of mature needles, and are covered by a frothy substance (Wilson, 1971;Coppel et al., 1974).
Larvae
The newly hatched larvae are 2.5 mm long, and fully grown larvae are 18 to 28 mm long. The male and female larvae have five and six feeding instars, respectively, with shiny-black head capsules. The fully grown larvae moult to the final non-feeding prepupal or pre-spinning larvae, which spin the cocoon. The body of L1 to L3 instars is uniform yellowish-green, with black thoracic legs. The L4 instar has a mottled colour pattern similar to the mature larvae. There is a double black mid-dorsal line extending the length of the body. On either side of the dorsal stripe is a yellowish stripe broken with transverse brown markings. Laterally the larva has a dark-brown to black field filled with numerous rounded yellow and white spots, many of which protrude from the surface of the body. The ventral side is pale-yellow. The body is sparsely covered with minute spines. The colours of the pre-spinning larvae are very light and pigmentation is strongly reduced.
Cocoon (pupa)
The cocoon is cylindrical with hemispherical ends. It is finely textured, somewhat glossy, and brown. The male cocoons are smaller (7.0 to 8.5 mm x 4 to 4.5 mm) than those of the females (8.5 to 10 mm x 4.5 to 5.5 mm), although there may be an overlap between the sexes. Mertins and Coppel (1972) used seed dockage sieves for the sex-separation of D. similis cocoons.
Adult
Male: 7 to 9 mm, black, abdomen ventral sometimes more or less rufous. Legs yellow, with the trochanters and basal two-thirds of the femora brownish-black. Antenna black with 22 to 24 segments, bipectinate. Penis valve: valviceps triangular, the breadth of the tip less than one-third of the base breadth.
Female: 7.5 to 10 mm, head and thorax mostly black, abdomen yellow and black. Colour pattern variable;some individuals almost dark. Legs yellow, femora partly fuscous. Antenna (including scapus) black, serrate. Lateral bands of the saw (annuli) with teeth (ctenidia) very regular and even.

Impact


The females of D. similis are poor fliers, therefore most of the expansion of this species in North America has resulted from the movement of infested nursery stock, trees, and foliage (Middleton, 1923;Coppel et al., 1974;Melcher and Townsend, 1999).


Source: cabi.org
Description


The morphology of the adult was addressed by Kumata (1963) and Kumata et al. (1983). The caterpillar chaetotaxy was described by Kumata (1993) and the morphology of the pupa was described by Gregor and Patocka (2001). The morphology of all the stages, including the larval chaetotaxy was studied by Sefrová (2002).
Egg
The egg is slightly elongated, ellipsoidal, and has a delicate pitting on the chorion surface. It is 0.32-0.37 mm by 0.23-0.27 mm. It is greenish-ochreous, which corresponds to the undersides of the leaves on the host plant.
Larva
The larval morphology corresponds to the morphology of other Phyllonorycter larvae. The larva is whitish-ochreous and is 4.0-5.6 mm long in the final instar. There are five larval instars. The first three instars are flat with reduced mouthparts and legs (sometimes called sap-feeding instars e.g. Kumata, 1978). The triangulate head capsule shows prognathy without spinneret, labial and maxillary palpi. There is a close group of stemmata on the head near the antennal base of these instars. The triangular mandibles with three curved cusps are moved horizontally between the huge flat labrum and the labium. The thoracic segments are strikingly dilated (especially in the first instar) compared with the abdominal segments. This characteristic decreases with the next instars. The final two instars (tissue-feeding instars) show the morphology of exophagous caterpillars. Their heads are more globular, semiprognathous and have complete mouthparts. The mandibles are more or less rectangular with five cusps on the frontal edge and they move vertically. The stemmata form a quadrangle. The thoracic legs, abdominal prolegs (on the third to fifth segments) and anal prolegs are normally shaped. The 23-38 claws of each proleg are positioned in multiple, usually irregular circles. The individual instars can be primarily distinguished according to the width of the head capsule: I: 0.14-0.16 mm;II: 0.18-0.21 mm;III: 0.25-0.28 mm;IV: 0.25-0.30 mm;and V: 0.31-0.40 mm.
Pupa
The pupa is light brown to brownish-black and 3.2-4.0 mm long. Its frontal process is short and broad. It is in the shape of an equilateral triangle with distinct surface sculpture. Abdominal segments two to eight bear two pairs of rigid setae and their dorsal parts are covered with coarse thorns. The male genitalia only slightly protrude. The tenth abdominal segment is long, with a broad anal field. This has an elongate cremaster, which is round in ventral view, and elongate and strongly constricted in lateral view, with one pair of small hooked thorns at the end.
Adult
The wingspan is 6.3-8.3 mm. The adult exhibits distinct seasonal dimorphism. The aestival form has a whiteish-ochreous frons and labial palpus. The hair tuft on the head is ochreous with individual white scales. The antennae are greyish-white with black circles. The thorax is golden-ochreous, with three white lines. The forewing is golden-ochreous, with a long and narrow basal streak (occasionally indistinct), lacking a dark margin, or with individual dark scales only on its fore margin. The first (basal) transversal streaks are narrow and slope outwards. The dorsal streak is distinctly longer than the costal streak. The other three costal streaks are located close to each other before the apex. The second dorsal streak, which is before the tornus, occasionally fuses with a light tornal spot. The basal margins of all the streaks are more or less bordered with black scales. A distinct line of black scales divides the yellowish-white cilia. The hind wings and their cilia are pale grey.
The winter form (differences only) has a hair tuft on the head that is greyish-black or black with individual white scales, and is entirely white. The thorax is dark brown, and occasionally has white scales and white, indistinct lines. The forewing is grey, greyish-brown or greyish-black, mixed with white and brownish-black scales or spots. The ground colour of the winter form is very variable from pale grey to brownish-black. This striking habitual seasonal difference is possibly due to the fact that the hibernating individuals easily escape the attention of their predators in overwintering shelters. No sexual dimorphism has been observed.


Source: cabi.org
Description

P. pinaster is a relatively large tree, 20-40 m tall, with an average diameter at breast height (dbh) at maturity of 35-40 cm. Crowns of old trees are wide and flat and the bole is clear over most of its length. Plantation trees have long, clean cylindrical stems in contrast to those of open-grown individual trees where trunks are broad at the base with a pronounced taper and increased branching. It has a deep tap root with secondary roots well-developed. The bark is thick, deeply fissured and dark red-brown. Needles are spiny, stout, stiff but not rigid, frequently twisted, occurring in pairs, with a vivid green colour. Flowers appear between late winter and mid-spring;male flowers usually abundant, clustered in shallow rings beneath the leaves with pollen shed in early spring. Female flowers occur on the tips of expanding shoots and are dull red in colour. Cones are nearly sessile, very oblique at the base, slightly curved ovoid-conic;shiny light-brown with scales and a broad transverse ridge rising to a central, small, upcurved prickle. Cones ripen between late summer and autumn, persisting closed on the tree for several years.

Impact

P. pinaster is regarded as highly invasive and its past and future behaviour have been modelled in regions where it is a serious problem. Prolific seed production, wind-dispersed seed and rapid growth rate all contribute to its ability to invade native habitats, which suffer a consequent reduction in species diversity. P. pinaster is reported to be an aggressive colonizer in Chile, Uruguay, Australia, New Zealand and South Africa. Binggeli (1999) regarded this as a highly invasive plant, while Rejmánek (1995) rated it as one of the five most invasive pines. Richardson et al. (1994) considered P. pinaster to be the most widespread invasive pine in South Africa, with much of the spread occurring on endangered fynbos vegetation.


Source: cabi.org
Description


Phytoplasmas are cell wall-less prokaryotes, too small in size to be resolved adequately by light microscopy methods. By transmission electron microscopy of ultrathin sections, phytoplasmas appear to consist of rounded to filamentous bodies bounded by a trilaminar unit membrane. These bodies contain granules the size of ribosomes and strands of DNA that apparently condense during specimen preparation (Thomas, 1979;Thomas and Norris, 1980). In phloem sieve tube elements of coconut palms, cells of the LY phytoplasma are generally 142-295 nm in diameter and may vary from 1 to 16 µm in length (Waters and Hunt, 1980).

Recognition


Because of a protracted incubation phase in palms (Dabek, 1975), visual examination for LY symptoms is insufficient to conclusively determine the disease status of palms. To date, no biological or serological tests for detection of the LY phytoplasma have been successfully developed. PCR is the most sensitive test currently available for phytoplasma detection although this diagnostic method is complicated by the unusually low pathogen titres in palm tissues. When symptomless, pre-bearing coconut palms were evaluated for natural infection by LY, monthly assessment of spear leaf samples by LY-specific PCR in a year-long study revealed phytoplasma titres reached detectable levels in these palms between 47 and 57 days prior to the appearance of visible foliar symptoms (Harrison et al., 1994c).

Symptons


Palm lethal yellowing disease involves a prolonged latent (incubation), 'symptomless', phase. The time from primary infection to appearance of overt visible symptoms on young, non-bearing coconut palms has been estimated as between 112 and 262 days (Dabek, 1975). About 80 days prior to symptom appearance, growth of infected palms is stimulated. This is followed by a period of gradual decline and then complete growth inhibition about 1 month before the end of the incubation phase.
The early stages of LY on coconut palms are accompanied by numerous biochemical and physiological abnormalities in roots that include marked fluctuations in respiration, total sugars and reducing sugars (Oropeza et al., 1995;Islas-Flores et al., 1999;Martínez et al., 2000;Maust et al., 2003). Decreased respiration and increased root necrosis occur prior to the appearance of any visible symptoms in above-ground portions of palms (Eden-Green, 1976, 1982). The onset of symptoms also coincides with alterations in phloem flux rates (Eden-Green and Waters, 1982) and changes in water relations (McDonough and Zimmerman, 1979;Eskafi et al., 1986) due to irreversible suppression of leaf stomatal conductance (Oropeza et al., 1991;León et al., 1996). Reduction of photosynthetic capacity is marked by decreases in photosynthetic pigments, growth regulators and activity of enzymes of the carbon reduction cycle (Dabek and Hunt, 1976;León et al., 1996).
Visible symptoms on the highly susceptible Atlantic tall (also known as Jamaica tall) coconut ecotype chronologically include premature shedding of all fruit (nutfall) regardless of their developmental stage. Aborted nuts often develop a brown-black calyx-end rot reducing seed viability. Premature nutfall is accompanied or followed by inflorescence necrosis. This next symptom is most readily observed as newly mature inflorescences emerge from the ensheathing spathe. Normally light yellow to creamy white in colour, affected inflorescences are instead partially blackened (necrotic) usually at the tips of flower spikelets. As disease progresses, additional emergent or unemerged inflorescences show more extensive necrosis and may be totally discoloured. Such symptom intensification results in the death of most male flowers and an associated lack of fruit set.
Yellowing of the leaves usually starts once necrosis has developed on two or more inflorescences (Arellano and Oropeza, 1995) and discoloration is more rapid than that associated with normal leaf senescence. Beginning with the older (lowermost) leaves, yellowing progresses upward to involve the entire crown. Yellowed leaves turn brown, desiccate and die. In some cases, the advent of this symptom is seen as a single yellow leaf (flag leaf) in the mid-crown. Affected leaves often hang down forming a skirt around the trunk for several days before falling. A putrid basal soft rot of the newly emerged spear (youngest leaf) occurs once foliar yellowing is advanced. Spear leaf collapse and rot of the apical meristem invariably precedes death of the palm at which point the crown topples away leaving a bare trunk. Infected palms usually die within 3 to 6 months after the appearance of the first symptoms (McCoy et al., 1983).
LY symptomatology may be complicated by other factors. For example, non-bearing palms lack fruit and flower symptoms. Foliar discoloration also varies markedly among coconut ecotypes and hybrids. For most tall-type coconut palms, leaves turn a golden yellow before dying whereas on dwarf ecotypes leaves generally turn reddish to greyish brown.
Nutfall and inflorescence-necrosis are early stage symptoms common to all other palm species affected by LY disease. Differences may occur in the stage at which spear leaf necrosis appears. For edible date palm (Phoenix dactylifera), death of the spear leaf usually precedes foliar discoloration whereas for Adonidia and Veitchia species, the spear is usually unaffected until after all other leaves have died. Two patterns of leaf discoloration have been described. Leaves yellow before dying in species such as fishtail palms (Caryota sp.), round leaf palm (Chelyocarpus chuco), gebang palm (C. elata), fan palms (Livistona and Pritchardia sp.), princess palm (Dictyosperma album) and windmill palm (Trachycarpus fortunei). In most other susceptible species, leaves turn brown rather than yellow. Irrespective of species, however, foliar discoloration generally advances from the oldest to youngest leaves in the crown (McCoy et al., 1983).

Hosts


Plant host range for LY phytoplasma (16SrIV-A) includes: Aiphanes lindeniana (Ruffle palm), Allagoptera arenaria (Kutze seashore palm), Caryota mitis (Burmese or clustering fishtail palm), C. rumphiana (Giant fishtail palm), Chelyocarpus chuco (Round leaf palm), Copernicia alba (Caranday palm), Corypha taliera (Buri palm), Crysophila warsecewiczii (Rootspine palm), Cyphophoenix nucele (Lifou palm), Dypsis cabadae (Cabada palm), D. decaryi (Triangle palm), Gaussia attenuata (Puerto Rican Gaussia palm), Howea belmoreana (Belmore Sentry palm), H. forsteriana (Kentia or Sentry palm), Hyophorbe verschaffeltii (Spindle palm), Latania lontaroides (Latan palm), Livistona chinensis (Chinese fan palm), L. rotundifolia (Footstool palm), Nannorrhops ritchieana (Mazari palm), Phoenix canariensis (Canary Island date palm), P. dactylifera (Date palm), P. reclinata (Senegal date palm), P. rupicola (Cliff date palm), P. sylvestris (Silver date palm), Pritchardia maideniana (Kona palm), P. pacifica (Fiji Island fan palm), P. remota (Remota loulu palm), P. thurstonii (Thurston palm), Ravenea hildebrantii (Hildebrants palm), Syagrus schizophylla (Arikury palm), Veitchia arecina (Montgomerys palm) and V. merrillii (McCoy et al., 1983;Eden-Green, 1997;Harrison and Jones, 2004;Harrison and Oropeza, 2008).
The LY phytoplasma (16SrIV-A subgroup) has also been experimentally transmitted to the following palm species: C. nucifera, P. canariensis, P. pacifica, P. thurstonii, T. fortunei and V. merrillii. Replicated transmissions to these palm species were achieved using the vector planthopper Haplaxius (syn. Myndus) crudus field-collected from palms in areas of high disease incidence in Florida, USA (Howard and Thomas, 1980;Howard et al., 1983, 1984).
Current knowledge of symptomless palm hosts include Thrinax radiata (Florida thatch palm) and Coccothrinax readii (Mexican silver palm) (Narvaez et al., 2006).
Although restricted primarily to the Arecaceae, the host range of the LY phytoplasma (16SrIV-A) also includes at least one non-palm host, namely the arborescent monocot Pandanus utilis (screwpine) (Thomas and Donselman, 1979;Harrison and Oropeza, 1997).
The host range of other coconut lethal yellows group (16rIV), subgroup phytoplasmas are as follows:
16SrIV-B subgroup - Acrocomia aculeata (coyol palm), C. nucifera (Roca et al., 2006);
16SrIV-C subgroup - C. nucifera (Lee et al., 1998);
16SrIV-D subgroup - Caryota urens (jiggery palm), P. canariensis (Canary Island date palm), P. dactylifera (date palm), P. reclinata (Senegal date palm), P. roebelenii (pygmy data palm), P. sylvestris (silver date palm), Pseudophoenix sargentii (buccaneer palm), Roystonea sp., Sabal mexicana (Mexican palmetto), Sabal palmetto (sabal or cabbage palm), Syagrus romanzoffiana (queen palm), S. romanzoffiana x Butia capitata (mule palm), Washingtonia robusta (Mexican fan palm) (Harrison et al., 2008, 2009;Rodriguez et al., 2010;Vázquez-Euán et al., 2011);
The host range of 16SrIV-D subgroup phytoplasmas includes the non-palm host Carludovica palmata (Panama hat or jipi palm) (Wei et al., 2007);
16SrIV-E subgroup - C. nucifera (Martinez et al., 2008);
The host range of subgroup 16SrIV-E phytoplasmas includes the non-palm hosts Cleome rutidosperma (fringed spiderflower), Cyanthillium cinereum (little ironweed cited as Vernonia cinerea), Macroptilium lathyroides (wild bushbean), Stachytarpheta jamaicensis (light-blue snakeweed) (Brown et al., 2008;Brown and McLaughlin, 2011).
16SrIV-F subgroup - Washingtonia robusta (Mexican fan palm), P. dactylifera (date palm) (Harrison et al., 2008).


Source: cabi.org
Description


The mycelium forms a 2-3 mm thick, felt-like pseudostroma on pod lesions and on solid culture media, which is covered by a dense mat of beige to tan spores which are powdery when mature. On modified V8 medium, growth rates range from 1.3 mm per day to 6.2 mm per day, while sporulation commenced after 5.0 to 13.8 days, depending on the isolate (Philips-Mora, 2003).
The mycelium is branched, septate, with basidiomycete-like dolipore septa. It forms the pseudostroma on the surface of external as well as exposed internal necrotic lesions. The hyphae are hyaline, 2-5 µm wide, slightly constricted at the septa. Sporogenous structures are either branched or unbranched, producing chains of spores which mature basipetally. On malt extract agar, spores are mostly globose (8-15 µm diameter), sometimes slightly ellipsoidal (8-20 x 5-14 µm), with thick (1-2 µm) walls (Evans et al., 1978), whereas Philips-Mora (2003) reported somewhat lower values on modified V8 medium. There, spore shape varied between isolates, with globose spores being most common (87% to 96%) in Peruvian and some Ecuadorian isolates, whereas Costa Rican and other Ecuadorian isolates had mostly (42% to 56%) ellipsoid spores (Philips-Mora, 2003).

Recognition


Given the devastating yield losses caused by frosty pod rot within a few years of disease establishment, growers in countries and regions free of the disease are anxious to maintain disease-free status and vigilantly reconfirm the absence of cream to tan pseudostromata on pods. Cocoa-producing countries particularly at risk of M. roreri introduction have developed measures for early detection and rapid response. The Dominican Republic, as the world’s largest producer of organic cocoa, linked its nation-wide diagnostic network with the incipient Caribbean Pest Diagnostic Network (Reyes Valentín et al., 2010). Brazil combined classical spore trapping with an enzyme-linked immunosorbent assay (ELISA) to detect the inconspicuous spores of M. roreri and distinguish them from other fungal taxa (Pomella et al., 2005). Sentinel stations near the borders with Colombia and Peru, where the disease is rife – far away from the cocoa-producing regions of Eastern Brazil – are proposed, in the hope that distant rapid response could win enough time to save the Brazilian cocoa industry from an invasion by M. roreri.
Early detection and a rapid response leading to eradication have never been applied successfully against frosty pod rot. After a latent infection phase of approximately seven weeks, there is an extremely narrow window of opportunity for early detection, as prolific sporulation occurs within one week of diagnostic symptom development. Thus, Krauss (2010) recommended training farmers as well as field officers in the recognition of early symptoms of frosty pod rot and offered tools for this purpose.
Where frosty pod is established, quantitative disease assessment involves the counting and removal of all pods that can be positively identified as infected with frosty pod rot. The aforementioned sliced pod assay can give diagnostic clarity.

Symptons


Symptoms appear only on pods, and their nature depends upon the age of the pods when infected. Pods that are infected very young 1 month) show slightly chlorotic swellings and sometimes distortion, followed by general necrosis before the pod reaches half size;the seed mass may become soft and watery.
Pods that are infected when 1-3 months old may show some swellings and/or distortion, and more generally large, necrotic, dark-brown spots with irregular borders, which grow rapidly and may cover all or part of the pod surface;larger pods show partial or total premature ripening. Necrosis spreads internally, particularly to the endocarp and placenta.
Pods that are infected after 3 months of age may show no external symptoms, or only limited necrosis, often slightly sunken, surrounded by areas of premature ripening. Infected pods are noticeably heavier than healthy ones. Internally, the endocarp, seeds and placenta may show more advanced, partial or total reddish-brown necrosis and the seed mass fails to separate from the endocarp. The pod surface remains firm in all cases.
Most of the necrotic external surface soon becomes covered by a thick, felty fungal growth (pseudostroma), at first frost-white, turning to cream, tan and then light brown. If an infected fruit is sectioned, the pseudostroma appears on the necrotic internal cut surfaces, followed by sporulation within a few days.
Infected pods remain attached to the branches and gradually shrink and dry, becoming necrotic, hard mummies, partly covered with the hardened remains of the pseudostroma.

Impact


The invasive basidiomycete pathogen M. roreri originated in Western Colombia/Ecuador. In recent years it has expanded its range in South America (Peru, Venezuela and Bolivia) and throughout Mesoamerica as far as Mexico. Africa, Asia and insular Caribbean are still free of this pathogen.

Hosts

M. roreri infects only the fruit of Theobroma and Herrania species. There is circumstantial evidence that flowers and flower cushions may harbour M. roreri, but it has never been isolated from such tissues (Evans, 1981;Ram, 1989). It has been inoculated into cocoa and other Theobroma seedlings and re-isolated from them (Evans, 1981;Ram, 1989), but no report has been found of natural infection of such tissues;it therefore does not sporulate on seedlings.


Source: cabi.org
Description

Colonies of Ascochyta fabae on PDA white to ash-white with sparse to abundant pycnidia;reverse cream to light brown. Colonies more yellow on oat agar. Mycelium abundant, velvety, composed of hyaline to yellowish, smooth, branched, septate hyphae. Pycnidia separate partially immersed, yellow to brown, subglobose to globose, 200-250 µm with usually one papillate ostiole. Conidogenous cells hyaline, short subglobose to cylindrical, arising from innermost layer of cells surrounding pycnidial cavity. Conidia hyaline, straight or slightly curved, base slightly truncated or rounded, one- or sometimes two- or three-septate, 16-24 x 3.5-6.0 µm, not constricted at septa.

Recognition

Symptoms of the disease are easily observed on leaves, stems and pods of plants in the field (see Symptoms). Where confirmation of the disease is required, surface-sterilized tissue from the edges of the lesions should be incubated on PDA to produce pycnidia containing one-septate spores. From older lesions, conidia can be obtained for microscopic examination by scraping the surface of lesions containing pycnidia into water on a glass slide.
If no structures are visible in leaf lesions, incubation of the leaves in a moist chamber overnight may allow distinction from chocolate spot caused by Botrytis fabae, which should produce characteristic conidiophores and conidia in lesions (Koike et al., 2006).
Seedborne infection can be detected by observing the characteristics of the colonies appearing after incubation of surface-sterilized seed on PDA (see Seed Health Tests).

Symptons

Symptoms occur on leaves, stems and pods. Where seedlings have grown from infected seeds, lesions are more obvious on the upper parts of the stem and on the older leaves. Lesions on the leaves are usually circular, dark brown and initially about 1 mm diameter. After a short time, the lesions become larger and slightly sunken with a pale-brown to dark-grey centre surrounded by a broad, dark, chocolate-coloured margin. As the spots enlarge, they become more irregular in shape and coalesce to cover larger areas of the leaf. Some zonation may occur within the necrotic area of the lesions, which may cause confusion with lesions of chocolate spot caused by Botrytis fabae. A more general browning of the vascular tissue of the leaf may occur as the lesions develop. Prominent, dark pycnidia develop within the lesions, particularly as the leaves age or when conditions are moist. The pycnidia can vary in abundance and are sometimes concentrically arranged.
On the stems, the lesions are usually smaller at the early stages of infection, but elongate up the stem and become markedly sunken. Stem lesions are usually darker than those on leaves, and contain scattered pycnidia. When the lesions are deeply sunken, either the stems of the plants may break at the point of infection, causing the plants to lodge or, if infection occurs at an early stage, the stems may bend upwards producing a kink where the stems regrow vertically. At the seedling stage, when infection originates from the seed, the combination of stem and leaf infection may result in the death of the plant.
As the pods develop, lesions can be produced over the surface. They become very deep with dark brown centres containing abundant pycnidia. In damp conditions, the conidial masses produced are pale pink to yellow. Well-developed lesions may penetrate the pod wall and affect seed set or may blemish the developing seeds within the pod. However, seed staining does not always indicate infection by the pathogen, because other saprobic organisms may invade the damaged tissue of the pod. Colonies of D. fabae can also frequently be isolated from unstained seed during routine seed health tests in the laboratory (A Biddle, [address available from CABI], personal observation, 2000).

Impact

Ascochyta blight is the most severe disease of cool-season pulses (Davidson and Kimber, 2007). D. fabae (anamorph: Ascochyta fabae) attacks Vicia faba and can survive and reproduce in and spread from crop debris or be transported in infected seed. Introduction on infected seed occurred in Australia and Canada in the 1970s, and was probably the means for the pathogen’s original spread to countries outside southwestern Asia. Ascospores are disseminated by wind from the debris as primary inoculum and secondary cycles are initiated by conidia spread by rain splash from plant lesions. The fungus is host-specific in causing disease, but may be able to survive in non-host plants and reproduce on their debris. It is not treated as a phytosanitary risk or listed as an invasive pathogen by major organizations. Seed certification is the primary means of preventing its spread to new areas and the importation of new genotypes of the fungus to areas already infested.

Hosts

The fungus is highly specialized to Vicia faba (broad bean or faba bean), and inoculations on other legume species have been largely unsuccessful (Yu, 1947;Sepulveda, 1993), although Gaunt (1983) did find that infections could be obtained under certain specific conditions. Despite numerous attempts to cross-infect other legume species, only a very few reports of limited success have been made. Bondartzeva-Monteverde and Vassilievski (1941) found only atypical lesions formed by a broad bean isolate on species other than bean. Sprague (1929) and Beaumont (1950) found that isolates obtained from broad bean induced symptoms on peas (Pisum sativum), but the conditions and methods under which the tests were made were not clearly defined. Wallen and Galway (1977) were unable to obtain infection of peas in the greenhouse in Canada.
Hernandez-Bello et al. (2006) found species from legumes to be host-specific in causing disease, but the fungi could be isolated from inoculated, but asymptomatic, non-hosts;Ascochyta fabae was isolated from pea and lentil plants. The possibility exists, then, that this pathogen could survive in non-host plants and even reproduce on the debris. Autoclaved chickpea stems have been used to obtain teleomorph production from mated A. fabae isolates (Kaiser et al., 1997).
A. fabae has been reported as infecting Onobrychis viciifolia (sainfoin) in southwest Asia (Sharifnabi and Fatehi, 1996;Eken, 2003). The identifications based on morphology need to be tested by inoculation of isolates onto V. faba.


Source: cabi.org
Description

M. gibsonii can be cultured on V8 juice + pine needle decoction agar, in natural light at 25°C (day), 0-10°C (night). Higher night temperatures (15°C) cause abnormal conidial formation (Suto, 1971). The fungus may also be cultured on PCA-UV at 25°C (Sullivan, 2010;Braun et al., 2013).
Stromata are dark-brown, tuberculated, filling the stomatal openings, 60-96 µm diameter. Conidiophores dense, dark-brown, straight or slightly curved, rarely septate and not branched;10-45 x 2.5 µm;conidiogenous loci unthickened. Conidia pale yellowish-olivaceous, long-obclavate, straight or slightly curved, 3-7 septate with a truncate or rounded unthickened base and obtuse tip;20-68 (mostly 40-50) x 2.5-4.5 µm (Ito, 1972). Asci bitunicate, clavate to cylindrical (33-) 35-38 x 5.5-7 µm, with thickened, bluntly rounded apex, rarely saccate and 32-36 x 6-8 µm, 8-spored, obliquely biseriate. Interthecial tissue present or absent (Evans, 1984). Ascospores hyaline, 1-septate, ellipsoidal to cuneate, (7.5-) 8.5 x 11 (-12.5) x 2 x 3 µm, guttulate (Evans, 1984).
Spermagonia are formed in discrete, unilocular stromata, or as locules in upper parts of large stromata (Ivory, 1987). They consist of a thin dark-brown wall enclosing white contents. The spermatia form on conidiogenous cells lining the inner wall of the locules, are hyaline, rod-shaped and 2-3 x 1 µm. They often become exuded in tiny hyaline droplets.
The fungus forms grey to grey-green or black, compact colonies which often become pulvinate and stromatic. They are mostly non-sporulating, although Asian isolates quite often produce brown, thin-walled spermagonia containing spermatia in a pale-grey slime when grown under black light. These isolates also produce conidia very occasionally in small fertile patches on stromatic colonies when exposed to black light. The African isolates grow more slowly, are more inhibited by black light, and are generally less spreading than Asian isolates (Ivory, 1987).

Symptons

Lesions can occur at any point along infected primary and secondary needles (Ivory and Wingfield, 1986). However, they often appear towards the distal part of the needles, especially on 1- to 2-year-old seedlings (Suto, 1979;Ivory, 1987). Ivory and Wingfield (1986) suggest that foliage of the lower crown is usually the most affected due to the occurrence of more favourable conditions for the infection. Observations in the Philippines by Koboyashi et al. (1978) indicated that the disease tends to start in the lower needles and spread to the upper crown later on.
Lesions are usually 5-10 mm long (Diekmann et al., 2002);they tend to progress initially from pale-green spots or bands, to a yellowish to yellowish-brown colour, followed by greyish to blackish-brown colour;eventually they coalesce, resulting in complete needle necrosis and eventual needle cast (Ivory and Wingfield, 1986;Ivory, 1987;Braun et al., 2013). Lesions on needles often lead to defoliation and can be especially damaging on young saplings;defoliation often leads to stunted growth and host plant death (Smith et al., 1997). Resulting necrotic needles are always without the reddish tint that is often characteristic of other infections of needles in Pinus species (CABI/EPPO, undated).
Dark-brown stromata fill the stomatal cavities, and numerous fruiting bodies appear as sooty spots on the lesions and, depending on their abundance, give a grey or black discolouration to the bands on the needles (Ivory and Wingfield, 1986). In warm, damp weather, small, grey brush-like tufts of elongate conidia may be just visible on the erumpent stromata (Ivory and Wingfield, 1986). Spermatia may also be extruded in tiny, clear droplets from spermagonia (Ivory, 1987). The distal portions of affected needles die rapidly and become colonized by various saprophytic fungi, whereas the proximal portions remain alive for some time (Ivory, 1987). Ivory and Wingfield (1986) also note that dead foliage may remain on the tree for many months but can be shed during high wind or heavy rain.

Impact

Mycosphaerella gibsonii is a fungal pathogen causing needle blight, primarily in Pinus species. It causes lesions on needles, first affecting lower needles and then spreading to the upper crown. The disease eventually causes needle necrosis and needle cast, leading to defoliation, stunted growth and host plant death;it is a major obstacle to the production of pine seedlings. M. gibsonii occurs in the tropics and subtropics of South and Central America, the Caribbean, sub-saharan Africa, India, South East Asia and East Asia;the native range is uncertain. Although natural dispersal by wind and water occur locally, international spread is largely due to movement of infected nursery stock. Phytosanitary control measures such as avoiding the planting of infected plants, removal and destruction of all infected pines in nurseries and cleaning between annual production cycles in nurseries can help to reduce the spread of the pathogen. It is listed as an A1 quarantine pest in the EPPO region, and is considered of quarantine significance in South America.

Hosts

M. gibsonii affects many species of Pinus. Additionally, it has recently been reported on Abies nobilis [ Abies procera ] in Japan (Farr and Rossman, 2018). It is particularly associated with old seedlings in tree nurseries, but is also quite common on older trees of highly susceptible species such as P. canariensis, P. radiata and P. roxburghii. Other susceptible species include P. halepensis, P. pinaster and P. sylvestris (EPPO, 2018). It also occurs on senescing foliage and leaf litter of many species at a much lower incidence level (Ivory, 1994).
During field surveys carried out by Ivory (1994) in Africa, Asia, Central America and Oceania, the fungus was found on Pinus ayacahuite, P. canariensis, P. caribaea, P. clausa, P. densiflora, P. elliottii, P. greggii, P. halepensis, P. kesiya, P. luchuensis, P. massoniana, P. merkusii, P. muricata, P. oocarpa, P. patula, P. pinaster, P. pseudostrobus, P. radiata, P. roxburghii, P. rudis [ P. hartwegii ], P. sylvestris, P. taeda, P. thunbergii and P. wallichiana. Other reported host species include P. cembra, P. contorta, P. echinata, P. flexilis, P. jeffreyi, P. lambertiana, P. mugo, P. nigra, P. parviflora, P. pinea, P. ponderosa, P. resinosa, P. rigida, P. strobus, P. taiwanensis, P. tabuliformis (Braun et al., 2013), P. maximinoi, P. morrisonicola, P. tecunumanii (Chen, 1965), P. armandii, Tsuga canadensis and Abies nobilis (Farr and Rossman, 2018).
It must also be noted that the following conifer species were found to be susceptible to the pathogen under artificial inoculation experiments: Abies veitchii, A. sachalinensis, Cedrus deodara, Picea glehnii, P. jezoensis, Pseudotsuga menziesii (Suto, 1979;Diekmann et al., 2002) and Larix kaempferi (Kobayashi et al., 1979;Suto, 1979;Diekmann et al., 2002).


Source: cabi.org
Description

Conidiophores solitary, fasciculate, or forming loose synnemata 12-45 µm wide, unbranched, septate, smooth, pale-brown to brown, (60-)120-240 x 4.5-7 µm, usually arising from a dark stroma, 30-60 µm diameter.

Recognition

The lower sides of leaves should be examined for the dark sporulation of the fungus in grey to brown sunken lesions with yellow halos;the lesions are also visible from the upper surface (Kuate, 1998). Mature fruits also bear sunken brown lesions with a yellow halo, with sporulation occurring under wet or humid conditions.

Symptons

On leaves, the fungus produces circular, mostly solitary spots, which often coalesce, up to 10 mm in diameter, with a light-brown or greyish centre when dormant and non-sporulating during the dry season, but becoming black with sporulation after the onset of the rainy season (Sief and Hillocks, 1993). The lesions are usually surrounded by a dark-brown margin and a prominent yellow halo;occasionally the centre of the lesion falls out, creating a shot-hole effect. At first glance, the young lesions appear similar to those of canker (caused by Xanthomonas campestris pv. citri), but differ in being flat or shrunken. Leaf spots, especially on younger leaves, often coalesce and together cause generalized chlorosis, followed by premature abscission and defoliation of the affected tree. Young leaves and fruit appear to be more susceptible than older mature leaves (Sief and Hillocks, 1999), but whether the leaves or fruit are more affected varies with the host species and variety (Bella-Manga et al., 1999) and location (Derso, 1999).
On fruit, the spots are circular to irregular, discrete or coalescent, and mostly up to 10 mm in diameter. On young fruits, infection often results in hyperplasia, producing raised tumour-like growths surrounded by a yellow halo;these develop central necrosis and collapse (Kuate, 1998). Lesions on mature fruit are normally flat, but sometimes have a slightly sunken brown centre. Diseased fruits ripen prematurely and drop or dry up and remain on the tree (Kuate, 1998). Infection by the fungus seems to predispose the fruit to secondary infection by Colletotrichum gloeosporioides (De Carvalho and Mendes, 1952;Seif and Kungu, 1990);it is common to find a dark-brown to black sunken margin of anthracnose around the fruit spots.
Stem lesions are not frequent and mostly occur as an extension of lesions on the petiole. Occurrence of several such lesions at the stem tip results in dieback;those on other parts of the stem coalesce, become corky, and crack. At the base of the dead stem there is usually a profuse growth of secondary shoots (Menyonga, 1971).

Impact

P. angolensis is a dematiaceous hyphomycete occurring in sub-Saharan Africa and Yemen. This fungus requires moisture for infection and the production of wind-borne conidia and causes a devastating fruit and leaf spot disease of cultivated species of Citrus. Losses of 50-100% of yield can occur and growers may cease production where the disease is endemic. Although species and cultivars of Citrus vary in susceptibility, no source of resistance is known (Kuate, 1998). An A1 quarantine pest for Europe and the Mediterranean region (EPPO, 2009), this fungus is also of concern for other warm humid regions where citrus is grown, such as Florida, USA. Other than by wind, conidia can be transported on infected fruit or propagated material.

Hosts

All species of cultivated Citrus appear to be susceptible, although the lime (Citrus latifolia) and smooth lemon (Citrus limon) are often reported to be relatively resistant. Of the other members of the Rutaceae in Africa, Citropsis tanakae is known to be infected (Kuate, 1998). The susceptibilities of the many wild Citrus species in Asia (USDA-ARS, 2009) remain unknown.


Source: cabi.org
Description


At rest the flatworm is broadest in the middle, tapering to each end. In cross-section, the back is gently convex and the belly is flat. Mature live specimens are approximately 40 mm long and 4 to 5 mm wide. Some specimens may attain a length of 70 mm. The mouth is just behind the mid-point of the belly, with a genital pore about half-way between the mouth and hind end. Two large prominent eyes are situated back from the tip of the elongate snout-like head. The back is light to dark olive-brown, and darkest on either side of the pale creamish-white stripe that runs along the mid-back and at the margins. The olive-brown colour grades to grey at the head end. A thin creamish-white stripe with fine greyish margins runs the length of the body along each side. The belly is creamish-white, with a white mid-ventral stripe. A pale sensory zone passes around the underside of the front end.
Newly emerged hatchlings are up to 8 mm long, with a pale brownish-grey colour extending dorsally and submarginally, a thin pale median dorsal stripe, white ventral surface, and prominent eyes.
A general account of the anatomy of a terrestrial flatworm is provided by Winsor et al. (2004), and detailed anatomical data for P. manokwari are provided by Winsor (1990, 1998d), and Kawakatsu et al. (1992).

Recognition


Terrestrial flatworms are normally detected by day by hand picking in moist microhabitats. Flatworms emerge at night to hunt and can be found with the aid of a spotlight or headlamp. Trapping methods for flatworms include laying plantain leaves or small boards directly on the ground;wetting areas of dry soil and covering these with a damp board (Ogren, 1955);or using a ceramic tile backed with 5 mm of polystyrene placed tile-down on the ground (Blackshaw, 1990). Polythene bags, 22 cm², and each filled with 1.5 kg of sand, were used to provide an artificial habitat to trap flatworms in New Zealand (Yeates et al., 1998), and conventional pitfall traps were successfully used in Tasmania to trap flatworms in a button grass habitat. Terricola can be extracted from soil samples using a 100 watt light bulb as a heat source (Ogren, 1955), but generally are not collected from soil or litter using dry extraction methods such as Berlese-funnel extractors. Extracting Terricola from soil samples using wet extractors such as those of Macfayden or Kempson (in Southwood, 1966) have potential, but appear not to have been reported. On-site formalin extraction (application rate of 4.5 litres of 0.2% formaldehyde per 1.2 m² quadrat, after Raw, 1959) was effective to a depth of at least 30 cm;the irritant bringing to the surface all specimens of a soil-dwelling flatworm species (Blackshaw and Stewart, 1992).
Bait traps can be useful for the detection of P. manokwari. Sugiura et al. (2006) placed land snails in 2-mm mesh nylon bags (approximately 30 x 25 cm) that allowed the entry of P. manokwari but not the escape of the snails. Five live land snails were placed as bait in each bag. When they checked bags three days after placement, they could find P. manokwari invading bags.

Impact

P. manokwari is a large predatory flatworm, originally discovered in New Guinea, which has been deliberately introduced into some Pacific islands in an attempt to control an invasion of the Giant East African Snail (Barker, 2002), but which has also been accidentally introduced to the soil of other Pacific countries. It has had a significant negative impact on the rare endemic land snail faunas of some Pacific islands, and has become established in a wide variety of habitats.

Hosts


The species occurs naturally on Mt Wilhelm at 3625 metres altitude and at Kainantu in the eastern highlands of New Guinea, Irian Jaya. The natural range of this upland species has not yet been determined.
In addition to hosts listed in the Host table of this datasheet, P. manokwari has been reported to prey on the following in the laboratory: Acusta despecta sieboldiana, Bradybaena similaris, Euhadra amaliae callizona, Euhadra peliomphala, Euhadra quaesita, Trishoplita conospira, Satsuma japonica, Euphaedusa tau, Pinguiphaedusa hakonensis, Zaptychopsis buschi, Discus pauper, Helicarion sp., Pythia scarabaeus, Zonitides arboreus (Kaneda et al., 1990), and Partula radiolata (Hopper and Smith, 1992). P. manokwari also preys on a pheretimoid earthworm in north Queensland, Australia.
P. manokwari feeds on live land snails of an endemic species of the Ogasawara Islands, Japan (Mandarina aureola) under laboratory conditions (Okochi et al., 2004). P. manokwari also feeds on live snails of the predatory species Euglandina rosea as well as other snail and slug species (Ohbayashi et al., 2005). Furthermore, P. manokwari feeds on dead earthworms, and thus can survive in areas where snails have been absent since their invasion (Ohbayashi et al., 2005;Sugiura et al., 2006). P. manokwari feeds on live flatworms of other species (Ohbayashi et al., 2005).


Source: cabi.org
Description

M. tuberosa is a woody vine, climbing, twining, 10-15 m in length, with abundant milky latex. Stems thick, cylindrical, glabrous. Leaves alternate;blades simple, 7-12 × 6-11 cm, 7-palmatilobed, the lobes elliptical, long-acuminate at the apex, the base cordiform, the margins revolute, slightly sinuate;upper surface dark green, slightly shiny, glabrous, with the venation sunken;lower surface pale green, dull, glabrous or puberulous, with the venation yellowish, prominent;petioles as long as the blade, cylindrical, glabrous or puberulous. Flowers functionally unisexual, solitary or in simple dichasia. Calyx yellowish green, the sepals unequal, 2-3 cm long, fleshy, accrescent and woody once the fruit is formed;corolla yellow, infundibuliform, 4-5 cm long, the limb 4-5 cm in diameter;stamens exserted, the anthers white;stigma bilobed, green, exserted. Capsules ovoid, opening irregularly, 1.5-2.5 cm long, light brown, with the sepals persistent and accrescent at the base;seeds 4 per fruit, black, obtusely trigonal, 1-1.5 cm long, velvety (Acevedo-Rodriguez, 2005).

Impact

M. tuberosa is a woody vine commonly cultivated as an ornamental which has escaped from cultivation and has become naturalized mostly in wet, mesic, and lowland forests in tropical and subtropical regions of the world (Austin, 1998;Wagner et al., 1999;Acevedo-Rodriguez, 2005). M. tuberosa is a fast-growing vine with the capability to reproduce sexually by seeds and vegetatively from discarded cuttings (PIER, 2014). Once established, it completely smothers tall forest canopies, killing host-trees and out-competing understory plants (Smith, 1985). It is included in the Global Compendium of Weeds (Randall, 2012) and is also listed as invasive in Florida, Cuba, St Lucia, Hawaii, and on several islands in the Pacific Ocean (Wagner et al., 1999;Florida Exotic Pest Plant Council, 2011;Graveson, 2012;Oviedo Prieto et al., 2012;PIER, 2014).


Source: cabi.org
Description

P. perfoliata is a prickly scrambling vine. It can reach a height of 6 m or more through climbing over shrubs and understory trees. The stems are elongated, branched and furrowed with short recurved prickles along the ridges. The thin, papery leaves are triangular, about 3-7 cm long and 2-5 cm wide, glabrous on the upper surface with prickles along the mid-rib on the underside (Zheng et al., 2005). The circular, saucer-shaped leafy structures, called ocrea, surround the stem at nodes. The inflorescences are capitate or spike-like racemes up to 2 cm long with clusters of 10 to 15 tiny flowers either terminal or in the axils of upper leaves (Kumar and DiTommaso, 2005). The flowers, 1-3 cm long, are borne on racemes. The fruits are attractive, deep blue and arranged in clusters at terminals, each containing a single glossy, black or reddish-black hard seed called an achene (NPS, 2009). Roots are fibrous and shallow.

Impact

P. perfoliata is a fast growing, spiny and herbaceous vine. Like many other members of the genus Persicaria, the plant is an aggressive and/or invasive weed. The plant scrambles over shrubs and other vegetation, and blocks the foliage of covered plants from available light, thus reducing their ability to photosynthesize. The leaves, petioles, and stems of P. perfoliata contain prickles, causing the movement of wildlife, and human activities to be impacted in infested areas (Okay, 1997). In its native China the plant has been used in Chinese medicine for over 300 years (Lou et al., 1988) and has rarely been recorded as an important noxious weed in either agriculture or the environment (Wang et al., 1990).

Hosts

P. perfoliata is not generally a weed of agricultural land (Wang et al., 1990), as it is removed during cultivation. However, the plant can be a pest in orchards, climbing on and covering horticultural crops. In the USA, the plant has a negative effect on Christmas tree farms, forestry operations on pine plantations and reforestation of natural areas (NPS, 2009).


Source: cabi.org
Description

L. maackii grows to be a tall shrub, up to 6 m high. The leaves are opposite, lightly hairy, and have long, acuminate tips. The leaves range in length from 5-8 cm and are dark green above, paler beneath. Pairs of fragrant, tubular, white to pinkish flowers, fading to yellow bloom from the leaf axils in mid to late spring. Bright red fruits 5-6 mm in diameter mature from late summer into autumn (Zheng et al., 2006). The bark is a light grayish brown on mature stems.

Impact

L. maackii is a species of honeysuckle native to East Asia and primarily invasive in central and eastern USA and in Ontario, Canada. It grows as a tall, deciduous shrub in dense stands along woods edges, in disturbed forests and along riparian corridors, outcompeting native species for resources. Few insects feed on the plant, but birds and mammals spread the fruits. It may have allelopathic affects on neighboring plant species. L. maackii was heavily promoted and planted from the 1960s to the 1980s in the USA, but its popularity has since declined. It is still available for sale at some nurseries and online. It is listed as a Class B Noxious Weed in Vermont and sale and planting are prohibited in Connecticut and Massachusetts, USA. L. maackii is critically endangered in parts of its native range in Japan.

Hosts


Under experimental conditions, extract of L. maackii showed allelopathic affects against seeds in the Brassicaceae family, but no crop species were tested (Cippolini et al., 2012).

Biological Control
<br>No known biological controls exist (Batcher, 2000). A study of fungi and arthropods on in China identified several species that live or feed on L. maackii (Zheng et al., 2006). Few North American insects feed on L. maackii enough to impact its growth (Lieurance and Cippolini, 2012;2013).

Source: cabi.org
Description


Adapted from Starr et al. (2003) and PIER (2013)

Impact

A. cordifolia is a succulent climbing plant native to South America that has proved to be very invasive in several countries where introduced, notably in Australia and on Pacific islands but also elsewhere. It smothers ground vegetation and, with its fleshy leaves and production of thick aerial tubers, it is so heavy that it easily breaks branches and can even bring down whole trees. It has shown itself to be a very damaging weed in moist forests, blanketing the ground and enveloping the canopy, restricting light and preventing the germination of native plants. A. cordifolia has been variously described as a ‘devastating weed’ that can ‘destroy a rainforest’. It has proved very difficult to control, but recent advances with biological control have shown potential following the release of the first agent in Australia in 2011.


Source: cabi.org
Light Pinus
Description

T. sibiricus is a small striped squirrel, weighing about 100 g (adults). It does not show sexual dimorphism. Young and adults are not distinguishable except by their size and proportions. Measurements (adults): In Russia (A. Lissovsky, Zoological Museum of Moscow University, Moscow, Russia, unpublished): body weight: 89.2 ± 2.1 g (range: 74Ð123, n =29), head and body length: 142.4 ± 2.0 mm (range: 124Ð168, n =28), tail length: 106.7 ± 1.5 mm (range: 90Ð133, n =30), hind foot: 33.6 ± 0.4 mm (range: 29Ð38, n =30), ear: 14 ± 0.5 mm (range: 9-19, n =30), condylobasal length of skulls from different parts of the range: 35 ± 0.05 mm (range: 32Ð39, n =381), zygomatic breadth: 21.9 ± 0.04 mm (range: 19Ð24, n =371). In France (B. Pisanu, MusŽum National d'Histoire Naturelle, Paris, France, unpublished): full body mass: 100 ± 1 g (range: 89 Ð 115, n = 33), head and body length: 149 ± 1 mm (range: 137 Ð 163, n = 28), tail length: 109 ±2 mm (range: 84 Ð 125, n = 24), hind foot: 36.4 ± 0.3 mm (range: 33.0 Ð 41.0, n = 28), ear: 16.3 ± 0.2 mm (range: 14.0 Ð 18.5, n = 26). Coat: T. sibiricus is a small squirrel-like animal with general sandy-rufous pelage coloration and a long bushy brown-grey tail, with a central and two pairs of lateral black stripes. The back from the back of the head to the rump is covered by five dark longitudinal stripes separated by lighter zones of the same width. Pelage coloration displays geographic variation;In central China the upper part of the head is greyish-brown with a slightly undulating pattern. The dark dorsal stripes are deep-brown with solitary light hairs. The central pair of light dorsal stripes is sandy-grey. The lateral pair of light dorsal stripes is light ash-grey. The medial part of the rump is rufous with a red tint.;In the Korean peninsula the upper part of the head is rufous-brown. The dark dorsal stripes are very contrasting, being deep brown, nearly black. The central pair of light dorsal stripes is rufous-fiery red. The lateral pair of light dorsal stripes is ochraceous-sandy. The rump is very bright, rufous-fiery red. The rufous color of the rump reaches the middle of the back in some specimens.;In the northern part of the range the upper part of the head is greyish-brown, fulvous-brown or rufous. The dark dorsal stripes are sharp black. The central pair of light dorsal stripes is sandy. The lateral pair of light dorsal stripes is sandy-grey. Southeastern populations have light dorsal stripes from ochraceous to red. Differences between the coloration of the central and lateral light dorsal stripes are weak. The medial part of the rump is brown, ochraceous-red or ochraceous (Obolenskaya et al., 2009).;Distribution;Top of page;The native range of T. sibiricus covers a vast territory from the northern parts of European Russia to the shore of the Sea of Okhotsk and from northern Yakutia to central China. A detailed description of the native range was published by Obolenskaya (2008). This publication includes the analysis of the distribution of this taxon, mainly based on localities recovered from available museum referenced specimens. The most western region where T. sibiricus is known to occur is the basin of the Severnaya Dvina. Occurrences in Karelia and Finland are not supported by museum collection information. In the eastward and southward directions, the border of the chipmunkÕs range in Europe follows the range of the southern taiga and does not cross the Volga. The northern border of its range coincides with the northern border of the taiga. T. sibiricus can also live in the forest-tundra zone but only along shrubby river valleys. It only inhabits the southern part of the Putorana Plateau and is not present north of 69¡ N. In the north-eastern part of the Far East, it inhabits mountain regions covered with Pinus pumila and is absent from the Chukotskiy Peninsula and Kamchatka. It lives along all the continental coast of the Sea of Okhotsk and the Sea of Japan. It inhabits Shantar Island, Sakhalin Island, Kunashir Island and Hokkaido Island. Further southward, it lives in broad-leaved and mixed coniferous and broad-leaved forests across the Korean peninsula and the Chinese provinces of Nei Menggu, Heilongjiang, Jilin, Liaoning, Hebei, Beijing, Tianjin, Henan, Shaanxi, Shanxi, Gansu, Ningxia, Qinghai and Sichuan. From Nei Menggu to the Altai Mountains, its range extends along the southern border of the taiga, including forested parts of Transbaikalia, Hentiyn Nuruu, Hangayn Nuruu and the Mongolian Altai Mountains along with part of the Chinese province of Xinjiang. Its range penetrates into the steppes along shrubby river valleys. West from the Altai, the southern border of the range goes along the southern limit of forested areas. It crosses the Novosibirsk, Omsk and Tyumen regions of Russia and reaches the southern Urals in the region of the Belaya River.


Source: cabi.org
Description


Perennial, climbing, woody vine with numerous lateral branches that climbs by means of tendrils and attains 5-8 m in length. Stems almost cylindrical, striate, glabrous;cross section with a single vascular cylinder. Leaves alternate, biternate;leaflets chartaceous, glabrous except for some hairs on the veins, the margins deeply serrate;terminal leaflet rhombic, 4.5-8 × 2-4 cm, the apex acute or acuminate, the base cuneate or attenuate;lateral leaflets oblong-lanceolate, 2.7-7 × 1.3-3cm, the apex acute or acuminate, the base obtuse or attenuate;rachis and petiole not winged, canaliculate;petioles 1-5 cm long;stipules minute, early deciduous;tendrils in pairs, spirally twisted, at the end of short axillary axes (aborted inflorescences), from which an inflorescence usually develops. Flowers functionally unisexual, zygomorphic, in axillary racemiform thyrses;cincinni more than 4, usually in more than one whorl. Calyx light green, of 4 sepals, the two outer ones ca. 1.7-3 mm long, the inner ones ca. 5-8mm long;petals white, obovate, 6-9 mm long;petaliferous appendages slightly shorter than the petals, fleshy and yellow at the apex, forming a hood that encloses the apex of the glands of the disc;disc unilateral, with 2 elongate glands, corniform, whitish, 1.2-2 mm long;stamens 8, the filaments unequal, glabrous or pubescent;ovary ovoid or ellipsoid, villous, with one style and 3 stigmas. Capsule membranaceous, inflated, ellipsoid or ovoid, 3-5.5 cm long, stramineous when ripe. Seed one per locule, spherical, black,4-5.5 mm in diameter, with a white, obtuse triangular hilum (Acevedo-Rodriguez, 2005).


Source: cabi.org
Title: Lemna minuta
Description

Structurally, the Lemnaceae are the simplest of the flowering plants. The plants are not differentiated into stems and leaves;instead, the plants in the family have an undifferentiated leaf-like body commonly referred to as a frond. Fronds floating, 1 or 2-few, coherent in groups, obovate, flat to thickish (but not gibbous), 0.8-4 mm, 1-2 times as long as wide, margins entire and thin, usually pale green, shining, nearly always with a sharp ridge with white papillae;veins 1, sometimes indistinct, very rarely longer than extension of air spaces, not longer than 2/3 of distance between node and apex;with or without small papillae along midline;anthocyanin absent;largest air spaces much shorter than 0.3 mm;turions absent. Roots to 1.5 cm, tip rounded to pointed, one root per frond;sheath not winged. Stipes (stalks) white, small, often decaying. Flowers within membranous cup-like spathes (open on one side) inside budding pouches located on either side of the basal end. Ovaries 1-ovulate, utricular scale open on 1 side. Fruits 0.6-1 mm, not winged. Seeds with 12-15 distinct ribs (Landolt, 1980;Flora of North America, 2008;Armstrong, 2009).

Impact

L. minuta is a small free-floating plant, no more than 3 mm in length. It is widely distributed in southern and western North America and is also found in Central and South America. It occurs in lowland ditches, ponds, canals, streams and rivers, and more rarely it is found in lakes (Preston and Croft, 1997). It often forms dense mats on the surface of water, reducing the light penetration and gas exchange, often causing the disappearance of submersed aquatic plants. Outbreaks are usually limited in time and space and are favoured by eutrophication. L. minuta is introduced in Eurasia (Landolt 2000) and it was first recorded in western France in 1965. From there it has spread all over Europe as far as southern Russia and Greece. It is also present in Japan (e.g. Landolt, 1986). It is considered a casual alien by Global Compendium of Weeds (2007). In many areas it is a noxious weed, as in Belgium, and it is included in the watch list with moderate impact (Branquart et al., 2007).


Source: cabi.org
Title: Lemna minuta
Description

S. minima is a deep-green, free-floating, rootless, aquatic fern (ISSG, 2006). Stems can be up to 6 cm and leaves are from 1-1.5 cm long and almost round to elliptic. They are obtuse or notched at the apex and round to heart-shaped at the base. The upward surfaces of the fronds are covered with stiff hairs, with four separated branches. The under surface of the leaves are brown and pubescent with slender and unbranched hairs (Flora of North America Editorial Committee, 1993). The stiff hairs on the fronds serve to trap air, thus providing buoyancy (Dickinson and Miller, 1998). Obscure veins are areolate and do not quite reach to the leaf edges. Sporocarps occur in groups of four to eight, with up to 25 megasporangia (Flora of North America Editorial Committee, 1993).

Recognition

S. minima is free-floating, which makes it easier to identify than most submerged aquatic vegetation. Volunteer monitors should be trained on the identity and habit of this potential invader.

Impact

S. minima is a very productive free-floating, non-rooted aquatic fern native to South and Central America. It was introduced outside its native range in southern Florida, USA in 1926 (USGS, 2005). The plant is degrading wetland ecosystems in several states of the USA (Tipping and Center, 2005). S. minima has an extremely high reproductive potential;the plants can rapidly colonize bodies of water, forming thick mats that displace native species, impact water quality, impede recreational activities, and clog waterways and irrigation channels (Rayachhetry et al., 2002). S. minima is also resistant to desiccation, allowing it to be transported long distances out of water (ISSG, 2006). The species can act as an annual, dying back when temperatures decrease and causing harmful nutrient pulses and dissolved oxygen crashes (Dickinson and Miller, 1998).

Hosts

S. minima is a highly competitive species with a very high growth rate. Colonies of S. minima can grow very densely, such that they shade light from valuable native submerged aquatic plant species (USACE-ERDC, 2002). Dense colonies can thus decrease local biodiversity and degrade the habitat (ISSG, 2006). The plant is also highly competitive among other free-floating species. A competition study specifically showed that S. minima had negative effects on the change in cover of the species Azolla caroliniana and Spirodela punctata (Dickinson and Miller, 1998). In Louisiana, USA native Lemna species were completely replaced by S. minima (ISSG, 2005).


Source: cabi.org
Description


Perennial, woody vine, 10-20 m in length. Stems are cylindrical, up to 2.5 cm in diameter, striate, puberulous;cross section of the stem with the pith hollow and the xylem tissue with wide rays. Leaves are opposite;blades 15-26 × 13-30 cm, ovate or broadly ovate, chartaceous, the apex acute or acuminate, the base cordiform, the margins lobate-dentate, ciliate;upper surface is dark green, shiny, puberulous, with slightly prominent venation;lower surface is light green, dull, glabrous or puberulous, with prominent venation;petioles 6-12 cm long. Flowers are arranged in axillary cymes;pedicels robust, cylindrical, 4-6 cm long;bracts light green, ovate, approximately 4 cm long, covering the calyx and the corolla tube. The calyx is green with the form of a ring, 4-5 mm long;corolla lilac-blue or white, with 5 lobes, the tube 6-7 cm long, light yellow inside, narrow at the base, the limb 6-7 cm in diameter. Fruits are capsules, approximately 3 cm long, subglobose at the base, the upper half in the form of a beak, explosively dehiscent in two halves (Acevedo-Rodríguez, 2005).

Impact

T. grandiflora is a woody vine included in the Global Compendium of Weeds and it is listed as a very aggressive weed impacting tropical and subtropical ecosystems (Randall, 2012). This species has been repeatedly introduced as an ornamental plant in many countries around the world, but it has become a serious environmental problem when it has escaped from cultivated areas and rapidly colonized natural habitats (ISSG, 2012). The rapid colonization of new habitat by this vine is mainly due to its capability to reproduce sexually by seeds and vegetatively by cuttings, fragments of stems and roots (USDA-NRCS, 2012). Once established, T. grandiflora completely smothers native vegetation by killing host-trees, out-competing understory plants, and negatively affecting the germination and establishment of seedlings of native species (Starr et al., 2003). Currently, T. grandiflora is classified as a “noxious weed” in Australia (Queensland Department of Primary Industries and Fisheries, 2007), and as an invasive species in Central America, the West Indies, Africa, and numerous islands in the Pacific including Hawaii, Fiji, French Polynesia, Palau, and Samoa (see distribution table for details;Acevedo-Rodríguez and Strong, 2012;ISSG, 2012;PIER, 2012).


Source: cabi.org
Description


Eggs
The eggs are spherical, somewhat flattened, and 0.6 mm in diameter. They are usually pale orange-brown or pink in colour, laid in batches and covered with hair scales from the tip of the abdomen of the female moth. Egg masses measure about 4-7 mm in diameter and appear golden brown because they are covered with body scales of females.
Larva
The larva is hairless, variable in colour (young larvae are light green, the later instars are dark green to brown on their backs, lighter underneath);sides of body with dark and light longitudinal bands;dorsal side with two dark semilunar spots laterally on each segment, except for the prothorax;spots on the first and eighth abdominal segments larger than others, interrupting the lateral lines on the first segment. Though the markings are variable, a bright-yellow stripe along the length of the dorsal surface is characteristic of S. litura larvae.
Larval instars can be distinguished on the basis of head capsule width, ranging from 2.7 to 25 mm. Body length ranges from 2.3 to 32 mm.
Pupa
The pupa is 15-20 mm long, red-brown;tip of abdomen with two small spines.
Adult
Moth, with grey-brown body, 15-20 mm long;wingspan 30-38 mm. The forewings are grey to reddish-brown with a strongly variegated pattern and paler lines along the veins (in males, bluish areas occur on the wing base and tip);the hindwings are greyish-white with grey margins, often with dark veins in S. litura (but without in S. littoralis). See also Schmutterer (1969), Cayrol (1972) and Brown and Dewhurst (1975).

Impact


The tobacco caterpillar, S. litura, is one of the most important insect pests of agricultural crops in the Asian tropics. It is widely distributed throughout tropical and temperate Asia, Australasia and the Pacific Islands (Feakin, 1973;Kranz et al., 1977). Records of S. litura having limited distribution in (or being eradicated from) Germany, Russian Federation, Russian Far East, the UK and Réunion may in fact refer to S. littoralis. Both S. litura and S. littoralis are totally polyphagous (Brown and Dewhurst, 1975;Holloway, 1989) and therefore have huge potential to invade new areas and/or to adapt to new climatic and/or ecological situations. The Spodoptera group consists of closely related species with similar ecology that are difficult to identify to species level.

Hosts


The host range of S. litura covers at least 120 species. Among the main crop species attacked by S. litura in the tropics are Colocasia esculenta, cotton, flax, groundnuts, jute, lucerne, maize, rice, soyabeans, tea, tobacco, vegetables (aubergines, Brassica, Capsicum, cucurbit vegetables, Phaseolus, potatoes, sweet potatoes and species of Vigna). Other hosts include ornamentals, wild plants, weeds and shade trees (for example, Leucaena leucocephala, the shade tree of cocoa plantations in Indonesia).
Both S. litura and S. littoralis are totally polyphagous (Brown and Dewhurst, 1975;Holloway, 1989).

Monitoring


Developments in pheromone technology have made it possible to monitor S. litura in the field, to improve on timing of plant protection measures within groundnut IPM programmes.
The identification of a male sex pheromone of S. litura, (ZE) 9,11-tetradecadienyl acetate and (ZE) 9,12-tetradecadienyl acetate by Youshima et al. (1974) has enabled effective monitoring of this species for several years. The basic work regarding trap design, height, longevity of the septa, and the potential role of this technology in groundnut has been thoroughly studied at ICRISAT Center, Hyderabad, India over the past decade. These studies have clearly indicated the migratory behaviour of the species in different areas. At present, pheromone technology has given high priority in monitoring for timing of plant protection measures within groundnut IPM programmes. The studies on trap density in groundnut situations indicated no significant differences in moth catches when there were four or more traps per hectare. No decline was noticed in moth catch with increase in trap density. This indirectly suggests a limitation in utilizing the technology in mass trapping operations (Ranga Rao et al., 1989).
However, there have been some promising results in monitoring the population of moths on Chinese cabbage (Yang Song et al., 2009);spraying times and costs of chemical pesticides against S. litura were significantly reduced by the adoption of sex pheromone trapping.
Population projections based on life tables and stage-specific consumption rates can reveal the stage structure and damage potential of the pest population of the moths (Tuan et al., 2014). This method could prove to be more reliable as the data obtained by pheromone traps. It is evident that these life tables have to be developed for each area where the moth occurs and one should take into account climate change and yearly temperature and rainfall patterns. It was already established that minimum temperature is the predominant factor that influences pheromone traps whereas wind velocity is predominant in light traps. The overall influence of all the weather factors was high in case of pheromone traps compared to light traps (Prasad et al., 2009).
Host-Plant Resistance
The development of resistance to S. litura in suitable groundnut varieties has been regarded as a high priority for Asian groundnut farmers for a number of years. The results of experiments carried out in 1986 and 1987 (data in Wightman and Ranga Rao, 1993) indicated the possibility that ICGV 86031 had some resistance to S. litura combined with high yield in the post-rainy season. This hope was substantiated in further tests on the ICRISAT research farm and in farmers' fields in coastal Andhra Pradesh (southern India). In the limited trials that have been carried out, farmers had sufficient confidence to grow this variety without protecting it with insecticides. They were rewarded with higher yields and lower variable costs than neighbouring farmers who grew locally acceptable varities but applied insecticides to kill defoliators. PI 269116, PI 269118 and PI 262042 had resistance to S. litura, but none were outstanding (Campbell and Wynne, 1980).
Bioassays carried out with larvae as preliminaries to detect the mechanism of resistance (independent tests by Ranga Rao (ICRISAT) and Padgham (NRI)) revealed no antibiosis effect on second- to sixth-instar larvae when fed mature leaves of ICGV 86031. The main mechanism of resistance is currently thought to be tolerance, manifested as the enhanced ability of vegetative tissue to regrow following defoliation.
However, first-instar larvae suffered 56% mortality when fed on ICGV 86031 compared with 12% mortality when fed on susceptible ICG 221. Padgham also found that newly hatched larvae had a marked propensity to vacate the leaves of this variety in the first 2 hours of free life. This suggests that the resistance factor which influences the neonates is associated with the leaf surface, because their feeding activity is restricted to scraping the leaf surface. The antixenosis demonstrated by ICGV 86031 is likely to increase the first-instar mortality that is characteristic of r-strategist noctuids (Kyi et al., 1991) and will therefore contribute to the determination of the level of damage caused by the older larvae among which mortality is comparatively low.
Amin et al. (2011) investigated the morphological and biochemical characteristics of three varieties of cotton and observed their effect on feeding and growth of S. litura. At least one variety was not suited for cotton growers. In a study of the interaction between the virus and the parasitoid, Guo Huifang et al. (2013) showed that the use of an appropriate concentration has the potential to improve the efficiency of the biological control.

Integrated Pest Management
<br>In recent years, due to crop failures experienced despite the use of several combinations of chemicals, an integrated approach based on cultural and biocontrol with efficient monitoring using pheromones has been developed (JA Wightman, ICRISAT, Andhra Pradesh, India, personal communication, 1996). The IPM technology that has been developed and implemented in irrigated groundnut where S. litura is endemic has the following components:<br>- clean cultivation to expose Spodoptera pupae to natural enemies and weather-related factors<br>- sunflower, taro (Zhou, 2009) and castor plants (that attract Spodoptera) to be sown as trap crops both around and within fields<br>- pheromone traps to predict Spodoptera egg laying<br>- mechanical collection of egg masses and larvae from trap plants on alternate days following the 'warning' from the pheromone traps<br>- application of fungicide (chlorothalonil) at the appearance of the first leaf spot lesions, and again after 10 days<br>- an application of neem kernel extract during the early stages of crop growth if necessary<br>- Pongamia glabra oil treatment on tomato plants gave significant reductions on the populations of S. litura while no adverse effects againsts it natural enemies (Marimuthu, 2008)<br>- application of nuclear polyhedrosis virus at 500 larval equivalents per hectare in the evening if needed.<br>Sahayaraj (2011) gives a summary of different types of plant extracts used by farmer on groundnuts and discusses their effiency.<br>Monitoring<br>Developments in pheromone technology have made it possible to monitor S. litura in the field, to improve on timing of plant protection measures within groundnut IPM programmes.<br>The identification of a male sex pheromone of S. litura, (ZE) 9,11-tetradecadienyl acetate and (ZE) 9,12-tetradecadienyl acetate by Youshima et al. (1974) has enabled effective monitoring of this species for several years. The basic work regarding trap design, height, longevity of the septa, and the potential role of this technology in groundnut has been thoroughly studied at ICRISAT Center, Hyderabad, India over the past decade. These studies have clearly indicated the migratory behaviour of the species in different areas. At present, pheromone technology has given high priority in monitoring for timing of plant protection measures within groundnut IPM programmes. The studies on trap density in groundnut situations indicated no significant differences in moth catches when there were four or more traps per hectare. No decline was noticed in moth catch with increase in trap density. This indirectly suggests a limitation in utilizing the technology in mass trapping operations (Ranga Rao et al., 1989).<br>However, there have been some promising results in monitoring the population of moths on Chinese cabbage (Yang Song et al., 2009);spraying times and costs of chemical pesticides against S. litura were significantly reduced by the adoption of sex pheromone trapping.<br>Population projections based on life tables and stage-specific consumption rates can reveal the stage structure and damage potential of the pest population of the moths (Tuan et al., 2014). This method could prove to be more reliable as the data obtained by pheromone traps. It is evident that these life tables have to be developed for each area where the moth occurs and one should take into account climate change and yearly temperature and rainfall patterns. It was already established that minimum temperature is the predominant factor that influences pheromone traps whereas wind velocity is predominant in light traps. The overall influence of all the weather factors was high in case of pheromone traps compared to light traps (Prasad et al., 2009).

Source: cabi.org
Description

Female: Length 1.45–1.6 mm. Dark brown with yellow markings. Head yellow, except gena posteriorly brown. Antenna pale brown except scape posteriorly pale. Pronotum dark brown. The mid lobe of mesoscutum with a ‘‘V’’ shaped or inverted triangular dark brown area from anterior margin, the remainder yellow. Scapula yellow. Scutellum, axilla and dorsellum brown to light brown. Propodeum dark brown. Gaster brown. Fore and hind coxae brown. Mid coxa almost pale. Femora mostly brown to light brown. Specimens from Mauritius are generally darker than those from Singapore. Oviposter sheath not protruding, short in dorsal view (Kim Delvare and La Salle 2004).
Male. Length 1.0–1.15 mm. Pale coloration white to pale yellow as opposed to yellow in female. Head and antenna pale. Pronotum dark brown (but in lateral view, only upper half dark brown;lower half yellow to white). Scutellum and dorsellum pale brown. Axilla pale. Propodeum dark brown. Gaster in anterior half pale;remainder dark brown. Legs all pale. Antenna with 4 funicular segments;without the whorl of setae;F1 distinctly shorter than the other segments and slightly transverse;about 1.4 wider than long. Ventral plaque extending 0.4– 0.5 length of scape and placed in apical half. Gaster shorter than female. Genitalia elongate, with digitus about 0.4 length of the long, exserted aedagus (Kim Delvare and La Salle 2004).

Impact

Unusual growths, caused by Erythrina gall wasp (Quadrastichus erythrinae), on leaves and young shoots of coral trees (Erythrina spp). alerts to the presence of this emerging invasive species. Quadrastichus erythrinae measures a mere 1.5mm and may be spread easily via infected leaves from infected Erythrina specimens.


Source: cabi.org
Description

Eggs
The egg of L. botrana is of the so-called flat type, with the long axis horizontal and the micropile at one end. Elliptical, with a mean eccentricity of 0.65, the egg measures about 0.65-0.90 x 0.45-0.75 mm. Freshly laid eggs are pale cream, later becoming light grey and translucent with iridescent glints. The chorion is macroscopically smooth but presents a slight polygonal reticulation in the border and around the micropile. The time elapsed since egg laying may be estimated by observing the eggs: there are five phases of embryonic development - visible embryo, visible eyes, visible mandibles, brown head and black head (Feytaud, 1924). As typically occurs in the subfamily Olethreutinae, eggs are laid singly, and more rarely in small clusters of two or three.
Larvae
There are usually five larval instars. Neonate larvae are about 0.95-1 mm long, with head and prothoracic shield deep brown, nearly black, and body light yellow. Mature larvae reach a length between 10 and 15 mm, with the head and prothoracic shield lighter than neonate larvae and the body colour varying from light green to light brown, depending principally on larval nourishment.
Older larvae are characterized by a typical dark border at the rear edge of the prothoracic shield (Varela et al., 2010) and by the black colour of the second antennal segment. The width of the head capsule is used to distinguish larval instars (Savopoulou-Sultani and Tzanakakis, 1990;Delbach et al., 2010) as well as mandible length (Pavan et al., 2010).

Recognition

Inspection of Grapevine Reproductive Organs
Inspect inflorescences and look for eggs or larvae on flower buds or glomerules. Inspect grapes and look for eggs or larvae, or damaged berries. It is easier to look for larval damage rather than for eggs, because detection of eggs is very tedious and time-consuming, especially under field conditions. Egg detection is always preferable when an insecticidal control has to be programmed.
Corrugated Paper Bands
This technique has sometimes been employed to trap and quantify overwintering pupae. Bands are placed around grapevine trunks or primary branches, and diapausing larvae pupate inside. However, this method is only useful in the last generation, and its reliability is uncertain.
Light Traps
Their lack of specificity makes their use inadvisable when the adult trapping methods described below are available. EGVM flight activity mainly occurs at dusk (Lucchi et al., 2018c);this negatively affects the visibility of the light traps, impacting on their efficiency.
Feeding Traps
These traps were largely used in the past before sexual traps were developed, but may still be useful in particular situations. Trapping females with food-baited traps is a valuable tool to predict the onset of oviposition, an event used to properly time insecticide treatments (Thiéry et al., 2006). An earthen or glass pot is baited with a fermenting liquid (fruit juice, molasses, etc.) and the scents produced attract adults which are then drowned;the population may be estimated by counting. Practical problems include irregularity in trapping because fermentation strongly depends on seasonal temperature, trap maintenance (lure replenishment and foam elimination), and low selectivity. Terracotta pots baited with red wine have been used in Spain to assess the L. botrana mating ratio in mating disrupted vineyards (Bagnoli et al., 2011).
Sexual Traps
Pheromone traps are easier to use compared to feeding traps. They are a sensitive tool to monitor flight of males exclusively, but can be useful to time an ovicidal treatment, and to properly schedule scouting activities in the vineyard. Sexual traps were first suggested by Götz (1939). Chaboussou and Carles (1962) designed traps baited with living L. botrana females, which became increasingly important for monitoring. To obtain a large number of females to bait traps, laboratory rearing methods were improved both on natural substrates (Maison and Pargade, 1967;Roehrich, 1967a;Touzeau and Vonderheyden, 1968), and on synthetic or semi-synthetic media (Moreau, 1965;Guennelon et al., 1970, 1975;Tzanakakis and Savopoulou, 1973). However, sexual trapping became more efficient when the major compound of the L. botrana sex pheromone, (7E, 9Z)-7, 9-dodecadienyl acetate, was described (Roelofs et al., 1973), identified from the female sex gland (Buser et al., 1974), and synthesized (Descoins et al., 1974). In traps, females were promptly replaced by dispensers impregnated with synthetic pheromone, which had essential practical advantages for monitoring. It has now been shown that the L. botrana sex pheromone is a blend of 15 compounds (Arn et al., 1988), but for economic reasons commercial traps incorporate only the major pheromone compound, which has a satisfactory trapping specificity for L. botrana. In Italy, males of few species of non target moths are sometimes captured in L. botrana pheromone traps (Ioriatti et al., 2004).
A major limitation of L. botrana sexual trapping (as often occurs in other insect pests) is the lack of a clear relationship between the number of males trapped and the damage done by their offspring, given the high number of other uncontrolled ecological factors involved. The correlation between these variables has been partially improved by diminishing the pheromone dose in traps (Roehrich et al., 1983, 1986). According to Roehrich and Schmid (1979), only a negative prediction can be made when male catches in traps are sporadic (or nil) can one expect minimal (or even no) damage to be caused by offspring on the crop;but if catches are moderate or high, the damage caused by offspring is unpredictable. Nowadays, the variable performance of the traps on the market, the influence of the trap placement and of the wind direction on the number of catches, make it still difficult to find a strict relationship between catches and infestation, especially when the catches are low.
Scouting
Forecasting models and moth trapping alone do not provide sufficient population density information and need to be supplemented with appropriate field scouting of eggs and young larvae (Shahini et al. 2010).
Insecticides are applied according to action thresholds (AT) on the basis of the resulting infestation assessment (percentage of injured clusters, number of nests per inflorescence, number of eggs and larvae per cluster, number of injured berries per cluster). The action thresholds vary widely depending on the generation, susceptibility of the cultivar to subsequent infection by B. cinerea, and whether berries are being produced for table grape, raisins or wine production.
Modelling
Predictive mathematical models have been developed and tested to forecast the life cycle of L. botrana, integrating both biological and climatic information. Temperature-based models, both linear (degree-days accumulated above a lower threshold) and non-linear (deterministic) have been generated in Switzerland (Schmid, 1978), France (Touzeau, 1981), Slovakia (Gabel and Mocko, 1984b, 1986) and Italy (Caffarelli and Vita, 1988;Baumgartner and Baronio, 1989;Cravedi and Mazzoni, 1990). Major problems affecting the correct inference of tortricid populations using modelling are summarized by Knight and Croft (1991) - it should be noted that prognosis is usually only qualitative. However, modelling can be a useful implement in L. botrana management programmes. Time of the first appearance of adults and hatching of the first eggs can be forecasted by predictive models based on temperature requirements of individual instars and critical conditions for oviposition (Moravie et al., 2006). Unfortunately, forecast models based on Degree Days are empirical and their robustness is strongly dependent on the environment in which they have been validated. Alternative forecasting techniques are currently under development, such as the evaluation of larval age distribution during the previous generation in order to predict the distribution of female emergence (Delbac et al., 2010).

Symptons

The following description refers to grapevine, on which symptoms largely depend on the phenological stage of the reproductive organs.
On inflorescences (first generation), neonate larvae firstly penetrate single flower buds. Symptoms are not evident initially, because larvae remain protected by the top bud. Later, when larval size increases, each larva agglomerates several flower buds with silk threads forming glomerules (nests) visible to the naked eye, and the larvae continue feeding while protected inside. Larvae usually make one to three glomerules during their development which provide protection against adverse conditions, i.e., insulation, rain and natural enemies. Despite the hygienic behaviour of larvae, frass may remain adhering to the nests.
On grapes (summer generations), larvae feed externally and penetrate them, boring into the pulp and remaining protected by the berry peel. Larvae secure the pierced berries to surrounding ones by silk threads to avoid falling. Frass may also be visible. Each larva is capable of damaging between 2 and 10 berries, and up to 20-30 larvae per cluster may occur in heavily attacked vineyards (Thiery et al., 2018). If conditions are suitable for fungal or acid rot development, a large number of berries may be also affected by Botrytis cinerea, Aspergillus carbonarius and Aspergillus niger, which result in severe qualitative and quantitative damage (Delbac and Thiery, 2016). Damage is variety-dependent: generally it is more severe on grapevine varieties with dense grapes, because this increases both larval installation and rot development.
Larval damage on growing points, shoots or leaves is unusual (Lucchi et al., 2011).

Impact

Lobesia botrana should be regarded as a potentially serious pest on a worldwide scale for all the vine-growing areas that are presently unaffected.

Hosts

The host plants listed for L. botrana have been compiled principally from Silvestri (1912), Voukassovitch (1924) and references therein;Ruíz-Castro (1943), Bovey (1966), Galet (1982), Stoeva (1982), Vasil'eva and Sekerskaya (1986), Moleas (1988), Savopoulou-Soultani et al. (1990), Gabel (1992) and Ioriatti et al. (2011).
Despite the wide host range recorded, grapevine is the major host crop in which damage is really important. With regard to wild hosts, Daphne gnidium is the major food plant (Lucchi and Santini, 2011). This species was thought to be the original wild host before the invasion of vineyards by L. botrana in the nineteenth century (Marchal, 1912), although this hypothesis has often been questioned (Bovey, 1966) and is still controversial.
Other hosts not selected naturally by females for egg laying have been tested satisfactorily under both laboratory and field conditions, constituting an adequate larval food;see, for example, Voukassovitch (1924) and references therein, including particularly studies by Dewitz, Wismann, Bannhiol and Lüstner;Bovey (1966) and Stavridis and Savopoulou-Soultani (1998).
However, some crops traditionally assumed in the older literature to be natural hosts of L. botrana, for example, Medicago sativa (lucerne) and Solanum tuberosum (potato), are not in fact naturally selected hosts.


Source: cabi.org
Description


Illustrated technical descriptions of adult and/or immature stages have been published by Cuscianna (1934), Tams and Bowden (1953), Frediani (1952) and Badolato (1976).
Eggs
Eggs are hemispherical (about 1.5 mm across), ribbed, white when newly laid, changing to orange-pink before hatching.
Larvae
Larvae generally develop through five or six instars but up to eight have been recorded in Egypt, plus an inactive prepupal stage (Hafez et al., 1970).
Full-grown larvae are up to 4 cm long, cream-yellow with pink suffusions. Larval chaetotaxy has been described and illustrated by Badolato (1976).
Pupae
Pupae are light brown, up to about 20 mm long, and with a terminal cremaster bearing one pair of long, fine spines and a smaller subsidiary pair. The pupae are often enclosed in a light, silken cocoon that is spun by the larvae before pupation.
Adults
Adult wing span is 26-40 mm, with males generally smaller than females. The forewings are pale whitish brown, variously marked with darker brown, and the hindwings are white. Male antennae are biciliate. The male and female genitalia are described and illustrated in Tams and Bowden (1953).
Tams and Bowden (1953) recognized three races of S. cretica: an ochraceous to ochraceous-buff form from the Balkans;a very pale yellowish-buff form from Morocco and the south-west Mediterranean, and a light cartridge-buff form with well-defined fuscous markings from Saudi Arabia, Somalia, Ethiopia and possibly Italy.

Recognition


Field infestations are easily detected by walking through crops looking for the symptoms (see Symptoms). Care must be taken to distinguish between dead hearts caused by shootflies (Atherigona spp.), chloropids and some plant pathogens, especially Fusarium. Identical symptoms are also caused by other species of stem borer and the presence of S. cretica is best confirmed by collecting larvae and pupae from damaged stems and rearing adults for identification by specialists.

Impact


The geographical range of S. cretica includes most of the countries and islands of the Mediterranean basin and extends through the Middle East and Arabia to Pakistan, northern India and northern Africa, extending south to northern Kenya and northern Cameroon. According to Tams and Bowden (1953) this species does not extend westward of Cameroon;however, earlier records from Mali, Niger and Togo have again been included on the recently revised CABI/EPPO (2001) distribution map. This is a pest species linked to graminaceous crops with a preference for sorghum, maize and sugarcane. It is present on wild Gramineae with a preference for Panicum repens. S. cretica could extend its range following these crops/wild hosts and in correlation with climatic change. More studies on the distribution of this species are necessary. It belongs to the 'Sesamia' group of noctuids, a group of very similar species that are difficult to identify, and therefore misidentifications can occur regarding new distribution data.

Hosts


Recorded host plants of S. cretica are mainly graminaceous crops, especially cereals. Sorghum is often its main host;in Israel a decline in the incidence of S. cretica has been attributed to reductions in the area of sorghum during the 1970s (Melamed-Madjar and Tam, 1980). In Egypt S. cretica is a major pest of maize and sugarcane (Hafez et al., 1970). It has also been recorded on carnations in Egypt (Temerak, 1982a), but this record from a non-graminaceous host has not been authenticated by subsequent authors.
Ahmed (1980) made preliminary field observations on 11 species of grasses and cereal crops in the El-Serw region of Egypt and concluded that Panicum repens was the most favoured host plant for S. cretica, followed by maize.


Source: cabi.org
Description

The length of workers is highly variable (Polymorphic) from 1.8 to 3.5mm. The body, from head to post petiole, is uniformly light yellow to dull brownish yellow. The gaster (swollen part of abdomen) is always darker. The head and body are mostly smooth, shining and unsculptured except on the very top of the head, which has fine transverse ridges (which are inconspicuous). The antennae have 12 segments, including a 3-segmented club. Club segments increase in size toward the apex. The eyes of M. destructor are relatively small, with 4-6 ommatidia in the longest rows. Mandibles have 3 strong teeth each;with a fourth tooth that is minute. Sparse body hairs cover the ant (Ferster et al. UNDATED;Harris et al. 2005).

Recognition


The Pacific Invasive Ant Key (PIAKey) manual Pacific Invasive Ants Taxonomy Workshop Manual can both be used in identifying invasive ants in the Pacific region.

Impact

Monomorium destructor (the Singapore ant) is described as a tramp ant as it is renowned for transporting itself around the world via human commerce and trade. Monomorium destructor is known to cause extensive economic damage in urban environments by gnawing holes in fabric and rubber goods, removing rubber insulation from electric and phone lines and damaging polyethylene cable.


Source: cabi.org
Description

W. auropunctata workers are monomorphic, which means they display no physical differentiation (Holway et al., 2002). The ants are typically small to medium-sized, with the workers ranging from 1-2 mm (Holway et al., 2002;Longino and Fernández, 2007). The little fire ant is light to golden brown in colour. The gaster (abdomen) is often darker. The pedicel, between the thorax and gaster, has two segments;the petiole and postpetiole. The petiole is 'hatchet-like', with a node that is almost rectangular in profile and higher than the postpetiole. The antenna has 11 segments, with the last two segments greatly enlarged into a distinct club. The antennal scape (the first segment) is received into a distinct groove (scrobe) that extends almost to the posterior border of the head. The propodeum has long and sharp epinotal spines (propodeal spines). The body is sparsely covered with long, erect hairs. This species is well-known for a painful sting, seemingly out of proportion to its size.

Recognition

Ants can be detected by conducting surveillance programmes in high risk sites with favourable ant habitats. Surveillance should not occur during or after rain when the ground surface is still wet. Inspection is unsuitable in excessively windy days when ant activity is minimal.
The following is adopted from Vanderwoude et al. (2009):
Three survey methods can be used to detect W. auropunctata: vial baiting, chop stick baiting and visual surveys.
Vial Baiting
Vial baiting with an attractant is systematic and most suitable for surveys of industrial sites and nurseries. Little fire ant vial baits contain peanut butter which can be made by smearing a line of peanut butter (half the size of a pea) on the inner side of each bait vial (60 cc plastic containers with lids). Baits should be freshly made as ants are are not as interested in old and dried-up baits. The survey is carried out by placing bait vials in a grid pattern, with a minimum of one bait container per 10 x 10 m grid. Bait containers should be placed in suitable ant habitats and should be collected within 60-90 minutes after placement in the field.
Chop Stick Bating
Chop stick baiting is useful when targeting habitat trees as well as individual potted plants. One end of the chopstick needs to be painted (both sides) so that these can be easily relocated in the field. Morning or overcast days are the best times to bait. If surveying at midday on hot, low humidity days, baits should be placed in shady spots.
Dip the unpainted end of a chopstick in peanut butter to get a light coating extending about halfway up the stick. Place the chopsticks with peanut butter on the ground every 5-10 m. Only place in suitable habitats such as bases of trees/shrubs and in shady spots. Leave chopsticks with peanut butter for at least 45 minutes, not more than 2 hours before collecting. While collecting check for presence/absence of W. auropunctata.
Visual Survey
Visual surveys are appropriate when targeting discrete locations within a large site or for covering large areas quickly. It is very efficient in high density areas. Causton et al. (2005) used hot-dogs (ca 5 mm thick, made of beef) on the lower ends of 30 cm wire flags that were placed on the ground at 5 m intervals along a transect to detect W. auropunctata. These baits were checked after 45 minutes.

Impact

Wasmannia auropunctata (the little fire ant) is responsible for reducing species diversity, reducing overall abundance of flying and tree-dwelling insects, and eliminating arachnid populations. It is also known for its painful stings. On the Galapagos, it eats the hatchlings of tortoises and attacks the eyes and cloacae of the adult tortoises. It is considered to be perhaps the greatest ant species threat in the Pacific region. This species has been nominated among 100 of the 'World's Worst' invaders.


Source: cabi.org
Title: Mus musculus
Description

A long tail (60-105mm - approximately equal to its head and body length of 65-95mm), large prominent black eyes, round ears and a pointed muzzle with long whiskers. Adults 12-30 g. Wild mice are commonly light brown to black;belly fur white, brown, or grey. Colour of tail also lighter below than above.

Impact

Mus musculus (the house mouse) probably has a world distribution more extensive than any mammal, apart from humans. Its geographic spread has been facilitated by its commensal relationship with humans which extends back at least 8,000 years. They do considerable damage by destroying crops and consuming and/or contaminating food supplies intended for human consumption. They are prolific breeders, sometimes erupting and reaching plague proportions. They have also been implicated in the extinction of indigenous species in ecosytems they have invaded and colonised. An important factor in the success of Mus musculus is its behavioural plasticity brought about by the decoupling of genetics and behaviour. This enables M. musculus to adapt quickly and to survive and prosper in new environments. This species has been nominated as among 100 of the "World's Worst" invaders.
Taxonomic Tree
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Domain: Eukaryota
Kingdom: Metazoa
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Rodentia
Family: Muridae
Subfamily: Murinae
Genus: Mus
Species: Mus musculus
Notes on Taxonomy and Nomenclature
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The taxonomy of the genus Mus is still not entirely clear and the last 30 years have seen a continuing reduction in the number of species recognised and a rearrangement of the phylogenetic tree. The confusion arises because of the gross morphological similarity of many Mus species, many of which are only (relatively) distantly related and the phenotypic plasticity within the various species themselves. It is now accepted that the genus Mus is actually comprised of 4 subgenera - Pyromys, Coelomys, Mus, and Nannomys - containing, in total, approximately 40 species plus an unknown number of subspecies (Nowak, 1991).


Source: cabi.org
Title: Mus musculus
Description

T. minutum is an extremely small, inconspicuous, drab brown, soft-bodied ant in the subfamily Dolichoderinae (Hymenoptera: Formicidae). The following characters can be used to diagnose it from all known invasive and introduced ants. Total length ca. 1.5 mm. Head width ≤0.45 mm. Antenna 12-segmented. Antennal scape length less than 1.5x head length. Eyes medium to large (greater than 5 facets), do not break outline of head in full-face view. Antennal sockets and posterior clypeal margin separated by a distance less than the minimum width of antennal scape. Anterior margin of clypeus distinctly concave. Mandible with distinct break in tooth size after fourth tooth dorsum of mesosoma with metanotal groove, but never with a deep and broad concavity;lacking erect hairs. Propodeum with dorsal surface distinctly shorter than posterior face;lacking posteriorly projecting protrusion. Waist 1-segmented (may be hidden by gaster). Petiolar node appearing flattened. Gaster armed with ventral slit;with four plates on its dorsal surface and with the fifth plate on the ventral surface. Distinct constriction not visible between abdominal segments 3+4. Hairs not long, thick and produced in pairs. Uniformly light to dark brown, often with paler brownish yellow appendages.

Impact

T. minutum is a very small (1.5 mm), inconspicuous, drab brown, soft-bodied ant that occurs in Australia and Oceania. The species is widely considered native across this region, but it is possible that part of its current range resulted from anthropogenic dispersal. The species is most commonly found foraging and nesting in disturbed forest vegetation, but is also known to occur on the ground and in primary forest. Although little is known about the biology of T. minutum and it is not on any alert or pest lists, the species has been implicated in the decline of two endangered butterfly species endemic to Micronesia, primarily through the predation of eggs and larvae. T. minutum belongs to a taxonomically difficult species-complex that requires additional study before any of the known populations can be conclusively considered invasive. The species is rarely reported from quarantine interceptions and is unlikely to pose a significant invasion risk.


Source: cabi.org
Description

Solenopsis papuana are very small monomorphic ants. They have a light reddish yellow to medium reddish brown colouration. The total length of workers is around 1-2mm. Antennae are 10-segmented with a 2-segmented club. Eyes are small to medium in size and contain less than 10 ommatidia. The mandibles can have 4 or 5 teeth. The head is subquadrate, and is longer than it is wide. The metanotal groove of this species is distinct and the petiole is higher than the postpetiole. All the dorsal surfaces of S. papuana have erect setae. The gaster is oval with the first segment longer than half the total length (Harris et al. 2005).

Recognition


The Pacific Invasive Ant Key (PIAKey) manual Pacific Invasive Ants Taxonomy Workshop Manual can both be used in identifying invasive ants in the Pacific region.

Impact

Solenopsis papuana is a native ant of the Pacific region that thrives in the company of other more major invasive ants, but is not a major pest species on its own. It has been introduced to Hawaii and has been able to invade intact forest land.


Source: cabi.org
Light Black streak
Description

The male house sparrow (Passer domesticus) has a brown back with black streaks. The top of the crown is grey, but the sides of the crown and nape are chestnut red. The chin, throat and upper breast are black and the cheeks are white. Females and juveniles are less colourful. They have a grey-brown crown and a light brown or buff eye stripe. The throat, breast and belly are greyish-brown and unstreaked (Cornell Lab of Ornithology, 2007).


Source: cabi.org
Description

The adult female of H. pungens is described and illustrated in Granara de Willink (1981) and Williams and Granara de Willink (1992). The larval instars are described and illustrated in Granara de Willink (1981). The adult female is about 3 mm long and oval to round (Hodges and Hodges, 2009). In life, the body contents of females vary in colour from pink to pink-yellow and the legs are light yellow, nymphs and males are deep pink (McFadyen, 1979) and the eggs are pink (Miller et al., 2014). The adult females are covered with a woolly, white mass of waxy threads, which protect them from predators. Lateral wax filaments are absent. The adult males do not resemble the females and have two semi-transparent wings and long ÔtailÕ filaments (ARC-Plant Protection Research Institute, 2002). Further validation characters are given in Williams and Granara de Willink (1992) and Miller et al. (2014). Authoritative identification requires slide-mounted adult females under a compound light microscope.

Symptons

H. pungens tends to live and feed on the growing tips or meristem of its cactus hosts. Initially the infested tips of the cactus stems grow abnormally and become twisted and distorted. Soon afterwards white, woolly masses appear on the tips of the stems. The distorted stems provide sheltered crevices which give protection to H. pungens (McFadyen and Tomley, 1981a). Infestations can lead to a change in hormone production within the plant, stimulating the production of lateral buds and leading to the generation of a gall-like structure. Stem growth and flower and fruit production is reduced or arrested in infested plants (US Fish and Wildlife Service, 2010;Zimmermann et al., 2010).

Hosts

H. pungens feeds on cacti in the family Cactaceae, including the genera Cereus, Cleistocactus, Harrisia, Hickenia, Parodia, as well as several other ornamental plant families, including Portulacaceae, Apocynaceae, Amaranthaceae and Euphorbiaceae (Williams and Granara de Willink, 1992;Hodges and Hodges, 2009;Triapitsyn et al., 2014a).

Biological Control
The most likely option for the control of field infestations of the pest is the use of biological control agents. Several parasitoids and predators have been identified as potential biological control agents of H. pungens (e.g. the cecidomyiid Kalodiplosis floridana, McFadyen, 1979, Zimmermann and PŽrez Sandi Cuen, 2010). Studies are being carried out in Puerto Rico to test the effectiveness of two parasitoids, the encyrtid Leptomastidea nr. antillicola and the cecidomyiid Diadiplosis coccidivora, to determine whether they should be considered for mass rearing and release efforts (CPHST Biological Control Unit, 2010). It is possible that specialized natural enemies of congeneric species in Mexico may prove to be suitable biological control agents if H. pungens were to invade Mexico.

Source: cabi.org
Light Yellows
Description

C. elegans is a slender, erect or infrequently decumbent palm, to 2 m tall or more but flowering when very small and less than 30 cm tall, then appearing stemless. Stem 0.8-1.5 cm diameter, green, densely ringed with prominent nodes, internodes 0.5-3 cm long. Leaves 5-8, spreading, pinnate, sheath 8-20 cm long, very obliquely open nearly to base and tubular only in lower 1/3, short ligule apically on either side of petiole, margins brownish and ragged, light green or whitish below margin, longitudinally greenstriate-nerved, petiole 10-40 cm long, slender, grooved and green above, rounded and pale below, rachis 15-60 cm long, very slender, 4-sided, angled and green above, rounded below with narrow yellow band extending onto petiole, pinnae 11-21 on each side of rachis, 15-30 ? 1-3 cm, linear to narrowly lanceolate, long-acuminate, contracted basally, thin, dark green, midrib prominent and pale, elevated or keeled above, 1-2 less prominent primary nerves on each side of midrib, secondaries numerous, faint.;Inflorescences erect, shorter than or equal to or greatly exceeding leaves, peduncles 15-90 cm long, 5-9 mm wide at base, ± flattened, 4-6 mm wide at apex, rounded, green where exposed in flower, red-orange in fruit. Staminate with 4-7 bracts, uppermost exceeding peduncle, largest to 35 cm long, acuminate and bifid apically, fibrous or ± papery, rachis 1.5-20 cm long, longitudinally ridged or angled, green, rachillae 5-35, lower ones the longest, these to 15 cm long, becoming progressively shorter toward apex of rachis, 2 mm diameter, spreading, simple or branched, sharply angled, green. Pistillate similar to that of staminate but with 6-10 bracts, rachis slightly shorter, flexuous, orange in fruit, rachillae fewer in number and shorter than those of staminate, to 10 cm long, ± stiff, green in flower, red-orange in fruit. Staminate flowers in remote to moderate spirals, 3 ? 4 mm, depressed-globose, yellow, aromatic, nerved when dry, sessile or slightly sunken in elliptic depressions, calyx 0.75-1 ? 2-2.5 mm, moderately lobed, green, petals 2.5 ? 2 mm, connate, corolla opening by a 3-angled pore apically, fleshy, stamens 1.5-2 mm long, filaments connate, whitish, anthers 0.75-1 mm long, entire, yellow, pistillode equal to or slightly exceeding corolla, 6-angled, flared slightly apically, pale yellow-green. Pistillate flowers in remote spirals, 3 ? 2.75 mm, globose, yellow, nerved when dry, slightly sunken in elliptic depressions 1-1.5 mm long, calyx 1 ? 2 mm, deeply lobed, green, petals 2-2.5 ? 1.5-2 mm, connate, corolla opening by a 3-angled pore apically, thick, fleshy, fruits 4-7 mm diameter, globose, black, seeds 3-6 mm diameter, globose (Hodel, 1992).


Source: cabi.org
Light Yellows
Description

C. sulphureus is an annual herb 0.3-2 m tall, taprooted. Stems erect, branched, glabrous or sparsely pilose to hispid. Leaves cauline, alternate, deeply lobed;petioles 10-70 mm long;blades 50-250 mm long;ultimate lobes 2-5 mm wide;margins sparsely spinulose-ciliate;apices apiculate. Synflorescences 100-200 mm long, spreading-ascending;bractlets linear-subulate 5-10 mm long with acute apices. Capitula 6-10 mm diameter;involucral bracts erect, oblong-lanceolate, 9-18 mm long with acute to rounded-obtuse apices;ray florets 8(+ in some cultivars) golden yellow to red-orange;laminae obovate, 18-30 mm long with truncate, denticulate apices;disc florets 6-7 mm long. Cypselae light brown, flattened, 1.5-3 mm long, hispidulous, rarely glabrous;pappus absent, or with two or three widely divergent awns, 1-7 mm long (description compiled from Beentje and Hind, 2005;Kiger, 2006;Chen and Hind, 2011;C Puttock, Smithsonian Institution, USA, personal observation).


Source: cabi.org
Light Yellows
Description

On favourable sites in its natural habitat A. auriculiformis grows 25-35 m tall with a straight bole dominant for a greater part of tree height. More commonly it is 8-20 m tall and rarely a shrub 3-5 m, heavily branched and with a short bole. The bark is grey or brown, sometimes blackened at the base, smooth in young trees, becoming rough and longitudinally fissured with age (Doran and Turnbull, 1997;Turnbull and Awang, 1997). The phyllodes are falcate, 8-20 cm long and 1.0-4.5 cm wide, glabrous, greyish-green and thinly textured. There are three prominent longitudinal veins running together towards the lower margin or in the middle near the base, with many fine, crowded secondary veins, and a distinct gland at the base of the phyllode (Pedley, 1975, 1978;Maslin and McDonald, 1996). The inflorescence is an axillary, somewhat interrupted spike to 8.5 cm long in pairs in the upper axils. Flowers are light-golden in colour, 5-merous, bisexual, tiny, sessile, fragrant;calyx tubular, up to 0.1 cm long, shortly lobed, glabrous;corolla to 0.2 cm long;stamens many, about 0.3 cm long;ovary densely pubescent. The pods are strongly curved to form an open coil, flat, flexible but hard, rather woody, glaucous, transversely veined with undulate margins and are about 6.5 cm long by 1.5 cm wide. They are initially straight or curved, but on maturity become twisted and irregularly coiled. The shiny black seeds, held transversely in the pod, are broadly ovate to elliptical, 0.4-0.6 cm long by 0.3-0.4 cm wide, and each is encircled by a long red, yellow or orange funicle;areole large, almost enclosed.


Source: cabi.org
Light Yellows
Description

Annual herbaceous plant, 30Ð60(Ð125) cm in height. Erect or ascending, stems stout, much branched, angular, glabrous. Leaves arranged spirally, simple, broadly ovate, elliptic to lanceolate, petiolate, 4Ð10 cm long, shortly cuneate to attenuate at the base, emarginate to obtuse or acute at apex. Leaf colour dark green, light green or red. Terminal leaves may be red, purple, yellow or variegated. Inflorescences borne terminal and axillary, globose cluster up to 2.5 cm in diameter, upper clusters form a terminal spike, male and female flowers intermixed. Flowers unisexual, subsessile with three tepals 5 mm long, with long awn. Male flowers have three stamens, female flowers have superior single celled ovary with three stigmas. Fruit ovoid-urceolate capsule, circumsessile below the middle, 3 mm long with single seed. Seeds ovoid, brown or black, smooth or faintly reticulate, lenticular in shape, 1Ð1.5 mm long (Grubben, 2004;Rahman and Gulshana, 2014;Ecocrop, 2018).


Source: cabi.org
Light Yellows
Description

H. elatus is a large evergreen tree up to 25 m high, tall straight trunk 0.4 m in diameter or larger. Leaves alternate with slender round leafstalks, 6Ð10 cm long, light green basal scales (stipules) 3 cm long, shedding early and leaving ring scar. Blades heart-shaped and nearly round, about 13Ð18 cm long and broad, abruptly shorter long-pointed at apex and heart-shaped or notched at base, with straight or finely wavy edges, with mostly nine main veins from base, slightly thickened, upper surface green and hair-less, lower surface gray hairy with 1Ð3 narrow glands near base of main veins. Flowers 1Ð3 borne at leaf bases at ends of twigs on stout green stalks of 13 mm, with light green hairy basal cup (involucre) 2 cm long with nine long-pointed lobes. Calyx 4Ð5 cm, light green, hairy, tubular with five narrow long-pointed spreading lobes. Petals five, yellow with large dark red spot at base inside, 9Ð13 cm long, narrow elliptical spreading, united at base. Stamens numerous on whitish column united with corolla at base. Pistil has densely hairy five-celled ovary, long style, and five rounded stigmas. Seed capsules egg-shaped, 2.5Ð4 cm long, blunt-pointed, densely hairy, splitting into five parts, calyx and involucre shedding. A red-flowered form is known there (Little and Skolmen, 2003).


Source: cabi.org
Light Yellows
Description

Annual, sometimes biennial herb containing bitter milky juice, producing a shortened stem with a rosette of large leaves when young. Rosette leaves alternate, sessile, thinly pubescent or glabrous, yellow or light to dark green, sometimes reddish along midrib, in escarole types, leaf-blade broadened, 10-25 cm x 8-15 cm, slightly crumpled, margin entire or dentate, in curly-leaved types, leaf-blade reduced, very narrow, deeply pinnatifid and strongly curled, both types form a loose head, usually creamy in the centre. In the generative stage, endive produces an erect branched stem, 50-150 cm high, with progressively smaller leaves. Inflorescence a terminal or axillary head, 1-3 together, sessile or peduncled, blue-flowered, involucre with outer row of 5 bracts, and inner row of 8 bracts, flowers all ligulate, numerous, stamens 5 with anthers fused. Fruit an obovate achene, 2-3.5 mm x 1 mm, with pappus of minute persistent membranous scales.


Source: cabi.org
Description

X. sagittifolium is a glabrous, erect, herb up to 2 m tall, acaulescent when young, mature plants with a thick, erect, fleshy stem up to 1 m long, these with numerous leaf scars and sometimes with aerial roots, the base enlarged, ovoid, producing lateral, elongated subterranean, edible tubers or corms. Leaves several, nearly in a rosette in acaulescent plants, or in a distal crown in mature plants;blades horizontal to slightly nodding, with the posterior lobes ascending, 40-100 ? 40-70 cm, simple, upper surface dark green with light green primary and secondary veins, lower surface light green, with dark green venation, the apex obtuse, ending in an acute point, the base cordate with non-overlapping lobes, the lowest pair of secondary veins surrounded by marginal tissue at their insertion with the petiole, the margins undulate;petioles erect, 1-1.5 m long, green, invaginate on lower 2/3, with straight, wavy or sometimes involute margins. Inflorescences 1-3, axillary, ascending;peduncles up to 20 cm long;spathe chartaceous, 13-15 cm long, the tube 6-7 cm long, grayish green, oblong-ovoid, the blade elliptic, erect, concave, adaxially cream to white, shortly acuminate at apex;spadix slightly shorter than the spathe, the pistillate zone cylindrical, the sterile staminate zone conical, pinkish, the fertile staminate zone elongated, ellipsoid, cream. Fruit a small, yellow berry (Acevedo-Rodr’guez and Strong, 2005;Langeland et al., 2008).


Source: cabi.org
Light Yellows
Title: Schinus molle
Description

Botanical descriptions are combined from a number of sources, including Mahoney (1990) and Vogt (1996). S. molle is a tree up to 15 m tall, often less than 10 m, with a spreading crown comprising drooping, pendulous twigs and weeping foliage. It is evergreen and unarmed. The bark is light grey-brown to dark brown, scaly or fissured, and peels to exude a sticky latex when damaged. The trunk, although often short, may be 2Ð4 m high and 60 cm in diameter. Branches tend to be brittle and may break in strong winds. The species is generally shallow rooted. Leaves are pinnate, alternate, imparipinnate, 25 (Ð 30) cm long, with a peppery smell when crushed, 12 Ð 15 (Ð 40) pairs of leaflets, linear-lanceolate, narrow, 3 Ð 4 (Ð 6) cm long. S. molle is dioecious. Flowers are very small, green-yellow in colour, with five sepals, arranged in lax, hanging, open panicles at the ends of branches. The fruit is a berry containing a single, small, black seed, spherical and 3 Ð 5 (Ð 7) mm in diameter, similar to a black peppercorn, in a thin red (purple to rose-coloured) shell, with a strong, peppery smell and sweet peppery flavour. The fruit hangs in dense clusters of many dozen seeds, and may be persistent on the tree (Ravindran, 2017)


Source: cabi.org
Title: Schinus molle
Light Yellows
Description

S. rivulatus is a demersal, gregarious and herbivorous fish that is commonly 5-25 cm long. The body is oval and laterally compressed and its standard length is 2.7-3.4 times its depth. The colour pattern is variable but typically grey-green to brown on the back, with a light-brown to yellow abdomen and fine yellow lines on each side with golden undulating streaks. It has small embedded scales on the body and a small first dorsal spine directed forward that is shorter than length of the snout and usually covered with skin. Teeth are in jaws in one series, incisor-like with lateral cusps.


Source: cabi.org
Light Yellows
Description

A. indica is a medium to large, deep-rooted, evergreen tree, to 15(30) m tall, with a round, large crown to 10(20) m in diameter;branches spreading;bole branchless for up to 7.5 m, up to 90 cm in diameter, sometimes fluted at base;bark moderately thick, with small, scattered tubercles, deeply fissured and flaking in old trees, dark grey outside and reddish inside, with colourless, sticky foetid sap. Leaves alternate, crowded near the end of branches, simply pinnate, 20- 40 cm long, light green, with 2 pairs of glands at the base, otherwise glabrous;petiole 2-7 cm long, subglabrous;rachis channeled above;leaflets 8-19, very short petioluled, alternate proximally and more or less opposite distally, ovate to lanceolate, sometimes falcate (2) 3.5-10 ? 1.2-4 cm, glossy, serrate;apex acuminate;base unequal. Inflorescence an axillary, many-flowered thyrsus, up to 30 cm long;bracts minute and caducous;flowers bisexual or male on same tree, actinomorphic, small, pentamerous, white or pale yellow, slightly sweet scented;calyx lobes imbricate, broadly ovate and thin, puberulous inside;petals free, imbricate, spathulate, spreading, ciliolate inside. Fruit 1 (or 2)-seeded drupe, ellipsoidal, 1-2 cm long, greenish, greenish-yellow to yellow or purple when ripe;exocarp thin, mesocarp pulpy, endocarp cartilaginous;seed ovoid or spherical;apex pointed;testa thin, composed of a shell and a kernel (sometimes 2 or 3 kernels), each about half of the seedÕs weight (Orwa et al., 2009).


Source: cabi.org
Light Yellows
Description

Rhizomes tuberous, aromatic, internally light yellow to yellow. Pseudostems 0.6-2 m tall. Leaves sessile or short-petiolate, sheaths glabrescent, green, blades broadly lanceolate or oblong-lanceolate, 15-40 ? 3-8.5 cm, glabrescent, acuminate at apex, cuneate at base. Inflorescence ovoid to ovoid-oblong or ellipsoid, 6-15 ? 2.5-5 cm, obtuse at apex, erect, 10-45 cm tall with 6-8 cataphylls, mature bracts broadly obovate or spatulate, broadest above middle, broadly rounded or obtuse at apex, 3-3.5 ? 2-3 cm, with red-lineolate margins, initially green, maturing red, bracteoles linear to lanceolate. Calyx 1.2-2.5 cm long, membranous, white, corolla 3.5-5.5 cm long, the lobes lanceolate, pale yellow to white, labellum 1.5-2.5 cm long, pale yellow to white, the central lobe emarginate, the lateral lobes free nearly to base. Stamen ca. 1 cm long, the connective ca. 8 mm long, ovary ca. 4 mm long, glabrous. Capsule ellipsoid or obovoid, 0.8-1.5 cm long, red (Acevedo-Rodr’guez and Strong, 2005).


Source: cabi.org
Light Yellows
Description

An evergreen tree up to 18 m tall (in cultivation, it is usually a dense bushy plant about 2-3 m high), bole low-branching, up to 60 cm in diameter, buttresses 60 cm tall, 70 cm deep, thin, light pinkish-brown, bark about 10 mm thick, strongly aromatic, the bark on young shoots is smooth and pale brown, on mature branches and stems rough, dark brown or brownish-grey, oil cells are located in the phloem, and are oval or round in cross-section, wood of mature trees varies from light brownish-grey to grey or yellowish-brown, without markings, more or less lustrous and faintly scented. Leaves opposite, somewhat variable in form and size, strongly aromatic, petiole 1-2 cm long, grooved on upper surface, blade ovate to elliptical, 5-25 cm x 3-10 cm, conspicuously 3-veined, or 5-veined, base rounded, apex acuminate, glabrous, coriaceceous, shiny dark green. Inflorescence consisting of lax axillary or terminal panicles up to 10 cm long or longer, peduncle creamy white, softly hairy, 5-7 cm long, flowers small, 3 mm in diameter, with foetid smell, pale yellow, subtended by small ovate hairy bract, perianth 8 mm long, silky hairy, with short campanulate tube and 6 persistent tepals about 3 mm long, fertile stamens 9, in 3 whorls, with 2 small glands at the base of the stamens of the 3rd whorl, a fourth innermost whorl consists of 3 staminodes, filaments hairy, stout, anthers 4- or 2-celled, ovary superior, 1-celled, with a single ovule, style short. Fruit a 1-seeded berry, ellipsoidal to ovoid, 1-2 cm long, black when ripe, surrounded by the enlarged perianth at the base.


Source: cabi.org
Light Yellows
Description

Shrub to 3-4 m tall, the branches with short scattered prickles. Leaves alternate bipinnate, pinnae 4-8 pairs, each with 7-11 pairs of elliptic, obtuse, obliquely inequilateral light green leaflets about 2-2.5 cm long, flowers red-and-yellow, or (var. flava) all yellow, the petals crinkly-edged, in long terminal racemes, filaments longer than petals, red, pod coriaceous, oblong, smooth, brown to black, to 10 cm long, several-seeded, seeds compressed, brown, usually 6-8 per pod [Stone, 1970].


Source: cabi.org
Light Yellows
Description

The colour of the perch depends on the habitat in which they live. In shallow areas where light penetration is good, they tend to be darkly coloured whereas in poorly lit areas without vegetation they are lightly coloured. Carotenoids, derived from crustaceans in the diet, sometimes make them deeply reddish-yellow. The dorsal surface is usually bright green to olive which extends down the sides in seven tapering bars. The sides are yellow to yellow-green and the ventral surface grey to white. The eyes are green to yellow, as are the caudal and dorsal fins. The first spine of the dorsal fin is often black and the membrane between spines one and two and that between the last four or five spines is also blackish. The pectoral fins are amber and transparent whereas the pelvic and anal fins are silver-white to yellow and opaque. Some perch have been observed to be entirely black. Male perch have thicker skin than females for most of the year (Lindesjšš, 1994). Regardless of sex, the epidermis is thickest in the prespawning period whereas the dermis is thickest after spawning. The body feels rough to the touch as a result of low mucus production and the presence of ctenoid scales. There are 51-61 scales along the lateral line.


Source: cabi.org
Light Yellows
Description

Erect, annual, blue-green, glabrous herb, up to 1.5 m tall, taproot up to 12 mm in diameter, all parts strongly smelling (herbaceous) especially after crushing. Stem subterete, up to 12 mm in diameter, much branched, sulcate, internodes often hollow. Leaves alternate, decompound, sheathed, sheath forming an open cone, embracing the stem at base, 1-3(-5) cm long, sulcate, petiole subterete, equally long or up to 13 cm longer than the sheath, lower leaves usually rather long petiolate, higher ones almost without petiole, blade triangular to ovate in outline, up to 30 cm x 50 cm, usually much smaller, pinnately divided into 2-6 pairs or whorls of primary pinnae and one top-pinna, each pinna again pinnately divided 2-4 times into linear or filiform, acute lobes of 1-60 mm x 0.1-1 mm. Inflorescence a compound umbel, 4-16 cm in diameter, peduncle up to 30 cm long, bracts and bracteoles usually absent, primary rays 5-35 per umbel, 1-10 cm long, unequal in length, longest ones at the outside of the umbel, secondary rays 3-35 per umbellet, 1-15 mm long, flowers bisexual, actinomorphic, some central ones often remaining rudimentary, protandrous (usually the styles and stigmas becoming fully developed after shedding of the corolla and stamens), calyx vestigial, sometimes 5 small teeth present on top of ovary, petals 5, distinct, subovate in outline, up to 1.5 mm x 1 mm, top strongly inflexed and notched, yellow, stamens 5, filaments about 1.5 mm long, yellow, pistil with inferior, bilocular ovary and a fleshy, conical stylopodium bearing 2 spreading styles about 0.5 mm long. Fruit a lens-shaped schizocarp, 2.5-6 mm x 2-4 mm, light or dark brown with a whitish to pale brown margin, splitting at maturity into 2 one-seeded mericarps which are attached at their top to an erect thin carpophore, mericarp flat, usually with 3 longitudinal prominent ridges and 2 flat, wing-like commissural ridges, on the commissural side, usually 2 dark brown longitudinal vittae, and on the dorsal side, between each 2 ridges, one vitta, the fruits are crowned by the persistent stylopodium and styles. Seed with testa adnate to the mericarp. Seedling with epigeal germination, hypocotyl 5-25 mm long, cotyledons opposite, linear, 15-50 mm x 1-2 mm, entire.


Source: cabi.org
Light Yellows
Description

Robust, perennial, glabrous, glaucous, aromatic herb, up to 2 m tall. Stem erect, terete, longitudinally striate, profusely branched at all heights, internodes hollow when older. Leaves alternate, decompound, sheathed, lower leaves largest, leaf sheath forming an open cylinder, at base embracing the stem, 2-15 cm long, margins white scarious, sheath much larger and fleshier in Florence fennel, rest of petiole subterete, 0-10 cm longer than the sheathing part, longitudinally striate, blade triangular in outline, up to 30 cm x 50 cm, 2-6-pinnately divided into filiform, acute, blue-green lobes 1-14 cm long, primary pinnae odd-numbered 3-19. Inflorescence a terminal, compound umbel, up to 20 cm in diameter but usually smaller, peduncle (1-)5-16(-24) cm long, primary rays 5-30(-70) per umbel, 0.5-12 cm long, unequal in length, the shortest ones in the centre, secondary rays (pedicels) (2-)10-30(-45) per umbellet, up to 1 cm long, unequal in length, involucre and involucels absent, calyx vestigial at the top of the ovary, petals 5, distinct, subovate in outline, up to 1.5 mm x 1 mm, with strongly inflexed, notched apex, yellow, with a thin membranous outgrowth on the ventral side of the midrib, stamens 5, about 1.5 mm long, pistil with inferior, bilocular ovary, 2 styles, each with a stylopodium at base and a stigma at top. Fruit an ovoid-cylindrical, usually slightly curved schizocarp, 3-8.5 mm x 2-2.5 mm, light green to yellow-brown, splitting at maturity into 2 mericarps each with 5 prominent ridges and oil-vittae between the ridges. Seed with testa adnate to the pericarp. Seedling with epigeal germination (Purwaningsih and Brink, 1999).


Source: cabi.org
Light Yellows
Description

S. luridus is a demersal herbivorous fish commonly 5- 25 cm long. Its body is compressed, deep and ellipsoid and its standard length is 2.1-2.8 times its depth. Teeth are in jaws in one series, incisor-like with 1 or 2 lateral cusps. No teeth on the palatine or on the vomer. The longest dorsal spine is longer than distance from front of eye to posterior edge of opercula and the longest dorsal ray is longer than length of snout. It has a small first dorsal spine directed forward and is usually covered by skin. Dorsal fin origin is above pectoral fin base. Caudal fin is truncated. Anal fin origin beneath 8-10 dorsal spines;its margin is round. Pelvic fin origin is behind pectoral fin base. Head is slightly concave with blunt snout. Mouth is relatively small with distinct lips. Maxilla is not reaching vertical of eye. The caudal fin is forked. It has small embedded scales. Its colour is variable but usually a grey-green to brown back, a light-brown to yellow abdomen and fine yellow lines on each side. Pectoral fins are hyaline-yellow with dark crossbars on caudal fins.


Source: cabi.org
Light Yellows
Description

Erect, annual, glabrous, usually profusely branching herb, up to 1.3 m tall with a well-developed taproot. Stem solid, subterete, up to 2 cm in diameter, older internodes sometimes becoming hollow, sulcate, mostly with a white bloom, light green with darker green ribs, occasionally violet. Leaves alternate, rather variable in shape, size and number, with a yellow-green, scariously margined sheath surrounding the supporting stem for up to three-quarters of its circumference, petiole and rachis subterete, sulcate, light green, blade white waxy, shiny green often with darker green veins, basal 1-3 leaves usually simple, withering early, often in a rosette, blade ovate in outline, deeply cleft or parted into usually 3 incised-dentate lobes, next leaves decompound, petiole 0-15 cm long, blade ovate or elliptical in outline, up to 30 cm x 15 cm, usually pinnately divided into 3-11 leaflets, each like the blade of the simple lower leaves or again pinnately divided into 3-7 simple leaf-like lobes, all higher leaves compound, petiole restricted to the sheath, blade divided into 3 leaflets of which the central one is largest, each often variously divided into ultimately sublinear, entire, acute lobes. Inflorescence an indeterminate, compound umbel, peduncle up to 15 cm long, bracts sublinear, 0-2, up to 11 mm long, primary rays 2-8, up to 4.5 cm long, bracteoles 0-6, linear, up to 1 cm long, secondary rays up to 20, up to 5 mm long, usually each umbellet has bisexual peripheral flowers, and the central flowers are sometimes male, calyx in all flowers represented by 5 small lobes, corolla with 5 white or pale pink petals, heart-shaped, very small (1 mm x 1 mm) in male flowers, in bisexual peripheral flowers usually 3 petals are larger: 1 petal develops 2 ovate lobes of about 3 mm x 2 mm and the 2 adjacent petals each develop one lobe, stamens 5, filaments up to 2.5 mm long, white, pistil rudimentary in male flowers, in bisexual flowers with inferior ovary, a conical stylopodium bearing 2 diverging styles up to 2 mm long, each one ending in a minutely papillate stigma. Fruit an ovoid to globose schizocarp, up to 5 mm in diameter, yellow-brown with 10 straight longitudinal ribs alternating with 10 wavy longitudinal ridges, often crowned by the dry persistent calyx lobes and the stylopodium with styles, fruit does usually not split at maturity, it contains 2 mericarps which each bear on their concave side 2 longitudinal, rather wide lines (vittae), containing essential oil. Seed 1 per mericarp, with testa attached to the fruit wall. Seedling with epigeal germination, taproot thin with many lateral roots, hypocotyl up to 2.5 cm long, cotyledons opposite, oblanceolate, up to 3 cm x 4 mm, pale green.


Source: cabi.org
Light Yellows
Description

E. umbellata is a deciduous shrub 2-4 (-5) m tall and 10 cm in diameter with slender, spreading branches, more or less spiny with thorns about 2.5 cm long. The bark is removable in longitudinal strips exposing the white hardwood underneath. An important distinguishing characteristic is that shoots and young branches are clothed with very attractive white silvery scales (lepidote), but which disappear with the rains. Leaves in clusters, elliptic to ovate-oblong, 4-8 cm long and 1-2 (-2.5) cm wide, upper surface sparsely white and covered with small scaly leaves (lepidote), lower surface densely white lepidote, apex acute to sometimes obtuse, petioles 0.5-1 cm long, densely white lepidote. Fragrant flowers appear in bunches of 1-7 in axillary umbels, white to light yellow, 8-9 mm long and 7 mm in diameter, perianth densely scaled, four-lobed;androecium comprising 4 stamens, very small, attached to the mouth of the corolla tube;gynoecium, simple, with one pistil, its average length being 7 mm, pedicels 3-6 (-8) mm long, elongating up to 12 mm long in fruit;hypanthium slender, gradually narrowed at base, 5-7 mm long;calyx lobes narrowly ovate, ca 3-5 mm long. Fruits, ovoid to globose, 3-9 mm long and 5 mm broad;epicarp, thin, covering the whole fruit;mesocarp, pulpy and juicy;pedicel, 5-6 mm long;freshly picked fruits, coral pink, seeds, 7-8 mm long and 2-3 mm in diameter, saffron yellow and approximately 26 mg in weight. Adapted from PIER (2008) and Parmar and Kaushal (1982).

Hosts

E. umbellata is known to invade pine plantations in the USA.


Source: cabi.org
Light Yellows
Description

P. macarthurii is a palm tree. Stems grow in dense clumps or rarely solitary, up to 9 m tall, only 7 cm in diameter, thus appearing bamboo-like. Leaves are up to 3 m or more long, compound. Leaflets are 15-40 on each side, more or less regularly arranged, with margins nearly parallel or tapered at the tip. Inflorescences are up to 20-45 cm long, bearing flowers in groups of three consisting of two male and one female flower. Male flowers with sepals 3, approximately 1.5-2.5 mm long, yellow-green to light green;petals 3, approximately 7 mm long, yellow-green to light green;stamens 23-40 per flower;ovary, style and stigma well developed but the ovules are absent in the male flowers. Female flowers with sepals 3, 2 x 3 mm, cream-green;petals 3, 3-4 x 2-3.5 mm, cream-green;3-6 staminodes present;stigma 0.5 mm long, recurved. Fruits ovoid, 12-16 mm long, red when mature. Seed 9-12 mm long, 5-angled.


Source: cabi.org
Light Yellows
Description

A. pavonina is a medium-sized to large deciduous tree, 6-15 m tall and up to 45 cm diameter, depending on location;generally erect;bark dark brown to greyish, the inner bark soft, pale brown, and the slash soft, white and fibrous;crown spreading;multiple stems common, as are slightly buttressed trunks in older trees, upper bole sometimes spirally fluted. Leaves are very large, bipinnate with a large swollen pulvinus;2-6 opposite or sub-opposite pairs of pinnae, each with 8-21 alternate leaflets on short stalks;leaflets 2-4.3 x 1 cm, oblong to ovate, with an asymmetric base and blunt apex, dull green above, light green beneath, turning yellow with age. Flowers in narrow spike like racemes, 12-15(-25) cm long;flowers fragrant, small, petals 5, oblong or elliptic, cream or whites lightly connate at the base, stamens 10, as long as the petals, the anthers tipped with minute glands. Legumes linear, flattened, 15-22 x 1.3-1.5(-2) cm with slight constrictions between seeds, dark brown, turning black upon ripening, leathery, dehiscent from top to bottom by twisting valves to reveal 8-12 hard-coated, vivid scarlet seeds, 7.5-9 mm in diameter, lens shaped;seeds adhere to pod. Ripened fruits can remain on the tree for long periods, sometimes until the following reproductive season (Orwa et al., 2009;PROSEA, 2012).


Source: cabi.org
Light Yellows
Description

M. oleifera is a small, fast-growing, drought-deciduous tree or shrub, often 8-10 m tall, sometimes to 12-18 m. It has a wide-open, typically umbrella-shaped crown, usually with a single clear bole, with smooth, light coloured or greyish-green bark. It tends to be deep-rooted (Dalla Rosa, 1993). Leaves imparipinnate, rachis 12-25 cm long, pubescent, 2-6 pairs of pinna 3-6 mm long, each with 3-5 pairs of pale green, obovate leaflets 1-2 cm long, terminal leaflets slightly larger, basal leaflet pairs sometime tripinnate (von Maydell, 1986). The foliage is light and moves in the slightest breeze giving light shade. The description by ICFRE (1995) of M. oleifera from India differs in part from that of African M. oleifera by von Maydell (1986), with more pairs of pinna (5-10 pairs) and leaflets (6-9 pairs). Sweet-scented flowers, cream white, arranged in panicles, with 5 unequal petals slightly larger than the sepals (von Maydell, 1986), yellow dots at the base (Vogt, 1996), petals narrowly spathulate, veined, white, bracts linear, calyx 5-lobed, linear-lanceolate, reflexed, puberulous outside, 5 stamens, fertile alternating with 5-7 staminodes, filaments villous at the base, ovary 1-celled, oblong, villous, ovules many, style slender (ICFRE, 1995). The long, pointed and triangular cross-section fruits are very distinctive, up to 1-2 cm broad, often 30-50 cm long, up to 120 cm long in some cultivated varieties, containing oily black seeds up to 1 cm in diameter in a typical 3-winged seed coat. Unripe green pods are somewhat fleshy, becoming fibrous and greyish when mature, persistent on the tree. In India, trees shed leaves in December-January followed by regrowth in February-March;flowering is in January-March with ripe fruits in April-June, but all year round in irrigated conditions (ICFRE, 1995).


Source: cabi.org
Light Yellows
Description

F. vesca is a perennial herb. Plants are erect, in rosette form, and 15-30 cm tall. Leaves are thin and light green, lighter coloured and slightly hairy underneath, with large sharp serrations. Flowers are white, 1.3 cm in diameter and are bisexual. The fruit is well-known: yellow or red, hemispherical with soft, pulpy flesh and highly aromatic. Seeds are small, raised and prominent on the outside of the flesh (Darrow, 1966;Hummer et al., 2011;Hancock, 1999). Flower parts are in whorls and the outer two whorls of the F. vesca flower consist of a whorl of five narrow bracts, alternating in alignment with an inner whorl of five wider sepals. Interior to the sepals is a whorl of five white petals. Flowers have 20 stamens (Hollender et al., 2012).


Source: cabi.org
Light Yellows
Description

Erect, slender, perennial herb usually grown as an annual crop, with a thickened, fleshy, subterranean rhizome and with one or more aerial leafy stems, up to 1.25 m tall. Rhizome robust fleshy, up to 2 cm thick, growing horizontally underground but at shallow depth, irregularly branched but normally only in the vertical plane, covered with deciduous, thin scales which leave ring-like scars, epidermis corky, pale yellow to reddish, irregularly wrinkled in the dried rhizome, flesh pale yellow, aromatic, on dried rhizomes scars of leafy stems visible as shallow cup-like holes. Stem erect, unbranched, mainly formed by the leaf sheaths, pale green, often reddish at base, scales covering the lower part oblong, about 6 cm x 1 cm, scarcely white-pilose outside, with prominent parallel veins and scarious margins. Leaves distichous, sheath prominently veined, densely appressed pilose, especially so in the upper part, with white, scarious, glabrous margins, ligule up to 5 mm long, bi-lobed, glabrous to sparsely pilose, scarious, blade linear to lanceolate, up to 30 cm x 2 cm, acuminate at apex, finely parallel-veined, glabrous above, scarcely pilose below, light to dark green. Inflorescence arises direct from rhizome, spiciform, 15-30 cm long, scape slender, 10-20 cm long, below the spike covered with scales as on the leafy stem bases, the upper ones sometimes with short leafy tips, spike ovoid to narrow ellipsoidal, 4-7 cm x 1.5-2.5 cm, light green, bracts appressed, ovate to elliptical, 2-3 cm x 1.5-2 cm, yellow-green, margin scarious, incurved, the lower ones with slender whitish acute tips, glabrous, finely parallel-lined, in the axil of each bract one flower may be produced, flowers fragile, short-lived, surrounded by a spatha-like bracteole, bracteole narrower and slightly longer than the bract, usually persisting and enclosing the fruit, calyx tubular-spathaceous, 10-12 mm long, whitish, corolla tubular, pale yellow, widening at top into 3 lobes, tube 18-25 mm long, dorsal lobe long ovate, 15-25 mm x 7-8 mm, with beak-like rounded apex curved over the anther, ventral lobes oblong, 13-15 mm x 2-3 mm, apex rounded, 3-veined, strongly recurved, labellum about circular in outline, 12-15 mm in diameter, tubular at base (tube 3 4 mm), 3-lobed above, central lobe obovate, 12 mm x 9 mm, side lobes elliptical, 5 mm x 3.5 mm labellum pale yellow outside, inside dark purple or red at top and at margins, mixed with yellowish spots, scattered pilose at throat, filament about 1.5 mm long, anther 2-celled, ellipsoidal, 7-9 mm x 3 mm, pale yellow, connectivum prolonged into a slender, curved, purple, beak-like appendage 7 mm long, enclosing the upper part of the style, ovary globose, 2 mm in diameter, 3-locular, style filiform, 3.5 cm long, white, slightly recurved and widening at top, ending in a funnel-shaped white stigma which is ringed with stiff hairs around its upper margin, 2-3 fleshy, sublinear, white nectaries, 5 mm long, are situated against the style on top of the ovary. Fruit a thin-walled capsule, 3-valved, red. Seed small, arillate, black.


Source: cabi.org
Light Yellows
Description

Erect, woody herbs or shrublets, 30-200 cm high, branches erect to horizontal, pinkish to light green, coarsely strigose, biramous hairs short, white, adpressed with equal arms. Leaves long, 5-7-foliolate, often basal leaves 3-foliolate, stipules 1-2 x 0.3-0.5 mm, narrowly triangular, hairy outside, petioles 1-2.5 cm long, canaliculate above, hairy, rachis 5-12 mm long, stipellae absent, petiolules 1-1.5 mm long, leaflets 3, very rarely 5, opposite. Racemes 5-15 cm long. Flowers pink to brick red, 4-5 mm long, bracts 1-1.5 mm long, narrowly triangular, caduceus, pedicels up to 1.2 mm long. Calyx adpressed white pubescent, cup 0.5-1 mm long, teeth 1-1.5 x 0.5 mm, narrowly triangular. Standard 3.5-4.5 x 3-4 mm, orbicular, sometimes broadly obovate, rounded and mucronate at apex, adpressed strigose on the back, wing petals 3-4 x 1 mm, glabrous ciliate along margins, keel petals 3-4 x 1-1.5 mm, strigose outside towards the tip, ciliate along margins, lateral spur ca 0.6 mm long. Staminal sheath 3-4 mm long, anthers approximately 0.5 mm long. Ovary approximately 3 mm long, linear, glabrous, up to 10-ovuled, style 1-1.5 mm long, glabrous. Pods more than 3 cm long, curved, dropping, seeds 6-10, approximately 2 x 1.5 mm, subtetragonous, yellow, dark-brown, smooth (India Biodiversity, 2014).


Source: cabi.org
Light Yellows
Description

A very variable, normally annual herb or subshrub, 0.5-1.5 m tall, erect, much branched, grown as an annual. Taproot strong, lateral roots numerous. Stem irregularly angular to subterete, up to 1 cm in diameter, much branched, often tomentose near branchings, green to brown-green, often with purplish spots near nodes. Leaves alternate, simple, very variable, petiole up to 10 cm long, leaf-blade ovate, up to 10(-16) cm x 5(-8) cm, acuminate at apex, margin usually entire, subglabrous, light to dark green. Flowers usually borne singly, terminal, pedicel up to 3 cm long in flower, up to 8 cm long in fruit, calyx cup-shaped, persistent and enlarging in fruit, usually with 5 conspicuous teeth, corolla campanulate to rotate with five to seven lobes, 8-15 mm in diameter, usually white, five to seven stamens with pale blue to purplish anthers, ovary 2(-4)-locular, style filiform, white or purplish, stigma capitate. Fruit a non-pulpy berry, very variable in size, shape, colour and degree of pungency, usually more or less conical, up to 30 cm long, green, yellow, cream or purplish when immature, red, orange, yellow, brown when mature. Seed orbicular, flattened, 3-4.5 mm in diameter, approximately 1 mm thick, pale yellow.


Source: cabi.org
Light Yellows
Description

G. sepium forms a small to medium-sized, thornless, deciduous, single- or multiple-stemmed tree;2-15 m and occasionally 20 m tall, and 5-30 cm and occasionally 1 m in stem diameter, with an open rounded crown, often greatly modified by lopping. The bark on young branches is smooth, grey-brown or pale whitish grey with raised pale brown lenticels, becoming fissured on boles. The leaves are alternate or sometimes sub-opposite, pinnate, 15-35 cm long, with slender, yellow-green, finely hairy rachis, an odd terminal leaflet, and 6-24 opposite (except in upper part of rachis) leaflets per leaf. Leaflets are narrowly elliptic to elliptic, rarely broadly elliptic, usually pointed at tips, 4.4-8.3 cm long, 1.7-4.8 cm wide, larger towards tip of the leaf, with characteristic dark purplish tannin patches scattered, especially on lower surface. The flowers are borne on erect, 2-15 cm long racemes arising from leaf axils, or on leafless nodes of older stems with almost synchronous maturation of 30-100 flowers on a single inflorescence. The flowers are typical of Papilionoid legumes, borne on short 5-11 mm long slender pedicels, 2 cm long, with a five-lobed campanulate (bell-shaped) calyx and a typical pea-shaped whitish-pink or purple corolla with five strongly unequal petals. The standard petal is light pink, or pink with a deep yellow basal blotch, and the blade is reflexed at 180¡ when the flower is fully open. The wing and keel petals are also usually pink. There are 10 whitish stamens, 9 united into a tube and one free. The pods are 10-17 cm long and 1.4-2.2 cm wide, strongly compressed, green sometimes tinged maroon and fleshy unripe, drying mid yellow-brown when ripe, and opening explosively when dry with the pod valves twisting into tight spirals after dehiscence. There are 3-10 lenticular, round or elliptic, yellow-brown, darker orange-brown when mature, seeds per pod, 8.5-11.5 mm in diameter.


Source: cabi.org
Light Yellows
Description

P. tomentosa is a large deciduous tree with an umbrella-shaped crown and grows to 10-18 m tall with a diameter at breast height of at least 1 m. Its bark is smooth and pale yellow to brown with numerous large lenticels when young, becoming rough and grey-brown with age, often with interlaced smooth areas that are often shiny. Olive brown to dark brown t wigs are stout and brittle, mostly glabrous except at the tip, around buds and along upper edges of leaf scars, lenticels pale, prominent, and elongated longitudinally. Deciduous l eaves are opposite, acuminate, cordate or broadly ovate, 20-30(-40) cm long, (10-)15-30 cm wide when mature, though leaves of stump sprouts may be twice as large, acute or obtuse, base cordate, margins entire or shallowly 3-5 lobed, sometimes toothed on small plants, pubescent and dull, light-green above, undersurfaces pale-green and tomentose. Terminal bud absent, axillary buds sunken in bark, winter buds with several outer scales, superposed. Cymes penduncled, the penduncles as long or longer than the pedicels, growing on the main axis and branches of paniculate inflorescences 40-60 cm long, though SE-EPPC (2003) observed the blossoms in much smaller upright clusters only 15-30 cm long and borne at the ends of stout, hairy twigs. Calyx deeply lobed, the lobes as long or longer than the tube. Flowers perfect, fragrant, showy, corolla 8-10 cm long, purple, tubular (or bell-shaped, SE-EPPC, 2003), pale violet with yellow stripes inside, with 5 shallow, rounded, unequal lobes. Brown fruit, ovoid, pointed, woody capsules 2.5-4 cm long borne in terminal clusters, with 2 carpels and numerous (up to 2000) tiny winged seeds attached to the 2 very large placentas. Seeds, tiny, winged, flat, 1.5 mm long.


Source: cabi.org
Light Yellows
Description

E. japonicus grows as an evergreen shrub or small tree that can reach up to 3 m, sometimes dwarfed. Branches are grey-green to grey-brown, terete glabrous and sturdy. Twigs are green to light green, glabrous, and not evidently striate, especially when fresh. The petiole is 3-10 mm long. Leaf blades are leathery or thickly leathery, ovate, obovate, orbicular-ovate or long ovate, measuring (3-)5-10(-12) x (2-)3-5(-5.5) cm, base orbicular or semiorbicular, margin crenulate distally, nearly entire proximally, apex orbicular or semiorbicular;lateral veins 6-8 pairs, slightly visible or unclear, especially when dry. Leaves are often variegated in cultivated varieties. Cymes usually axillary, sometimes terminal, many branched with many flowers;peduncle up to 8 cm, sub-branches 2-4 cm;pedicel 4-7 mm. Flowers are 4-merous, 5-6 mm in diameter;sepals nearly orbicular;petals greenish white or yellowish green, sometimes cream, nearly orbicular. Capsule globose or subglobose, brown or yellow-brown to red-brown, 6-9(-12) mm in diameter, 4-lobed. Seeds 2 per locule, 5 x 3.5 mm, dark brown, globose;aril orange-red (Flora of China Editorial Committee, 2017).

Biological Control
E. japonicus is damaged by a wide range of insects, pathogens and nematodes but there are no reports of attempts at exploiting these for biological control.

Source: cabi.org
Light Yellows
Description

D. erecta is a sprawling or vine-like tender evergreen shrub or small tree, growing up to 7 m tall and spreading to an equal width (Munir, 1995;Floridata, 2015). It typically grows in a clump with multiple branches that droop towards the ground (Floridata, 2015). The bark is light brown and slightly furrowed (Andreu et al., 2010). The stems of mature plants usually have sharp axillary thorns, which are absent in younger plants of this species (Missouri Botanical Garden, 2018). Leaves are ovate, paired, opposite, and between 2.5 and 7.6 cm long (Floridata, 2015). Flowers hang in long racemes (approx. 15 cm) and are small, tubular and range from purple and white to violet or blue (Andreu et al., 2010). The fruit is approximately 7-10 mm in diameter, subglobose or obpyriform and is orange-yellow in colour (Munir, 1995).


Source: cabi.org
Light Yellows
Description

Morinda citrifolia is a small tree or large evergreen shrub approximately 3Ð10 m in height at maturity and 15 cm or more in stem diameter. The plant sometimes finds support on other plants as a liana. The sapwood is soft and yellow-brown and the bark relatively smooth to slightly rough and grey or light brown. The light green, four-angled twigs have opposite, pinnately veined, glossy leaves attached by stout petioles, 1.5Ð2 cm long. Stipules are connate or distinct, 10Ð12 mm long, the apex entire or two- to three-lobed. The membranous, glabrous leaf blades range from elliptic to elliptic-ovate and range in size from 20 to 45 cm long and 7Ð25 cm wide. The tubular flowers are perfect, with about 75Ð90 in ovoid to globose heads. Peduncles are 10Ð30 mm long;the calyx a truncated rim. The corolla is white, five lobed, with the tube greenish white, 7Ð9 mm long and lobes oblong-deltate, approximately 7 mm long. There are five stamens, scarcely exserted and the style is about 15 mm long. Fruit (a syncarp) are yellowish white and fleshy, 5Ð14 cm long, about 3Ð7.5 cm in diameter, soft and fetid when ripe. Seeds are brown, about 4Ð9 mm long and have a distinct air chamber. The plant has a rooting habit similar to citrus and coffee, with an extensive lateral root system and a deep taproot (Janick and Paull, 2008).


Source: cabi.org
Light Yellows
Description

H. tiliaceus is a small evergreen tree, 4-10 m tall, with a broad crown of widely spreading or crooked branches, or a shrub with many prostrate branches forming dense thickets. Trees have smooth grey or light brown bark with fibrous inner bark, on a short crooked trunk to 15 cm in diameter. Twigs are stout, with rings at nodes, becoming brown and hairless. Young twigs, leafstalks, lower leaf surfaces, calyx and seed capsules densely covered with minute whitish grey, star-shaped hairs. Leaves are alternate, petioles 5-13 cm, with two large short-pointed whitish hairy basal scales (stipules) 2.5-4 cm long, shedding early and leaving a ring scar. Leaf blades 10-18 cm long and broad, sometimes larger, abruptly short- or long-pointed at apex and heart-shaped at base, rarely wavy toothed on edges, slightly thickened and leathery, shiny yellow-green and hairless on upper surface, lower surface with three narrow glands near base of main veins. Flower clusters (panicles) at or near ends of twigs, branching. Flowers many, few in each cluster, each with whitish hairy stalk 2-5 cm and grey-green hairy basal cup (involucre) 2 cm long, usually with 9-10 narrow pointed lobes. Calyx 2.5-3 cm long, grey-green, hairy, tubular with five narrow long-pointed lobes. Petals five, yellow, usually with dark red spot at base inside, 6-9 cm long, rounded but broader on one side, with tiny star-shaped hairs on outer surface, united at base. Stamens numerous on column, about 5 cm long, united with corolla at base. Pistil has densely hairy, conical five-celled ovary, long slender style and five broad stigmas. Flowers open and close on the same day, the petals withering and turning to orange and later to red. Seed capsules elliptical, 2.5-3 cm long, long-pointed, grey-green hairy, splitting into five parts and breaking open the calyx and involucre which remains attached. Seeds, three from each cell, brownish black, 3-5 mm long, hairless. (Adapted from Little and Skolmen, 1989).


Source: cabi.org
Description

H. polysperma is an herbaceous rhizomatous perennial aquatic plant with squarish stems that are ascending or creeping. The stems are mostly submerged, and are usually rooted in the substrate, though can also root freely at floating nodes. The submerged stem is very brittle, and can grow over 6 feet long. The submerged leaves are opposite along the stem, and are sessile with the bases joined at the nodes by ciliated flanges of tissue. The leaves are elliptic to oblong, light green, sparsely hairy, and usually broader towards the tip. Leaves are up to 8 cm long and up to 2 cm wide (UFL-IFAS, 2005), and the leaves on the submersed stem tend to be considerably larger, wider, and lighter in color than those on immersed stem. The small bluish white flower is nearly hidden by leaves in the uppermost leaf axils, and is 2-lipped, with the upper lip being 2-lobed and the lower lip 3-lobed. The fruit is a narrow hairy capsule up to 9mm long, containing 20-30 seeds, each seed being approximately 0.4-0.62 mm long, 0.3-0.5 mm wide, and 0.002-0.06 mm thick. The seeds are compressed, obovate to elliptic to round, with the entire margin narrowly winged. The seed coating is minutely pebbled, glistening, orange-yellow to brown-yellow, and translucent where the seed is particularly thin (FNW Disseminules, 2007).

Impact

H. polysperma is an aquatic, mostly submerged, partly immersed plant that can grow to form dense stands and floating mats which cause many negative environmental and economic impacts. Some of these impacts include displacing native plant species, reducing biodiversity, decreasing water quality and flow, clogging irrigation pumps, impeding recreational activities, and diminishing aesthetic value. H. polysperma is extremely difficult and costly to control, and its ability to form new plants vegetatively facilitates its spread to new locations. The trade and potential escape of H. polysperma through the aquarium and water garden industry plays a large role in its spread to new locations, as does the transportation of this plant on recreational equipment or by wildlife moving between water bodies (DCR, 2003). H. polysperma is declared a noxious weed in the United States (USDA-NRCS, 2006), and is currently well established in Florida and parts of Texas. H. polysperma has also been recorded in Virginia, though current status of this population is unknown (Sutton, 1995). H. polysperma has recently been recorded for the first time in Europe (Hussner et al., 2007), and has the potential to spread to new locations throughout the continent.


Source: cabi.org
Description

D. unguis-cati is a woody vine with tendrils, 10-15 m length. Stems are cylindrical, lenticellate, up to 6 cm in diameter;cross section of the mature stem with multilobed xylem, the lobes alternating with radially arranged phloem tissue;nodes thickened;interpetiolar zone not glandular. Pseudostipules are ovate, approximately 5 mm long. Leaves are opposite, 2-foliolate, with a terminal tendril, trifid like a claw, generally of short duration;leaflets 6-16 x 1.2-7 cm, elliptical, oblong or obovate, chartaceous or coriaceous, glabrous or with punctiform scales, the apex acute or acuminate, the base acute, rounded, or unequal, the margins undulate or rarely denticulate;upper surface dark, shiny, with sunken venation;lower surface light green, dull, with prominent venation;petioles 1-4.5 cm long, petiolules 0.5-2.5 cm long, both glabrous. Flowers are solitary or in pairs, axillary;pedicel 2 cm long. Calyx is green, campanulate, 12-16 mm long, with five unequal lobes;corolla brilliant yellow, infundibuliform, 4-8 cm long, the limb 3-6 cm in diameter, with five unequal lobes, rounded;4 stamens, didynamous, inserted;ovary covered with punctiform scales. Capsule is linear, somewhat woody, brown, 25-95 cm long;seeds numerous, 1-3.5 cm long, with two membranaceous wings (Acevedo-Rodríguez, 2005).

Impact

Dolichandra unguis-cati is a vigorous, woody vine that can climb up to 15 m or higher. Due to its showy yellow flowers, it has been widely introduced as a garden ornamental. It has escaped from cultivation and become a significant invader of cultivated orchards, riparian corridors, natural forest remnants and disturbed areas, such as roadsides and urban spaces. D. unguis-cati clings tenaciously to any substrate with adventitious roots and clawed tendrils. This vigorous growth allows it to sprawl over other vegetation and, through a combination of both shading and weight, it can kill even large canopy trees. In the absence of climbing support, D. unguis-cati grows along the ground forming a thick carpet that inhibits the growth and seed germination of native understorey vegetation including native grasses, herbs and seedlings of shrubs and trees. Currently, this vine species is listed as invasive in Kenya, Malawi, Tanzania,South Africa, Australia, New Zealand, India, China, Mauritius, New Caledonia, Cuba, the Bahamas and the USA including Hawaii, Florida and Texas (Kairo et al., 2003;Henderson, 2001;Weber et al., 2008;Weeds of Australia, 2011;Oviedo Prieto et al., 2012;Randall, 2012;PIER, 2016).

Biological Control
Biological control programmes were initiated in 1996 in South Africa and in 2001 in Australia (Shortus and Dhileepan, 2011). Biological control against D. unguis-cati has resulted in the release of two lace bugs, Carvalhotingis visenda and C. hollandi (Hemiptera: Tingidae), a leaf-mining beetle Hedwigiella jureceki (Coleoptera: Buprestidae), a leaf-tying moth Hypocosmia pyrochroma (Lepidoptera: Pyralidae), a seed-feeding weevil Apteromechus notatus (Coleoptera: Curculionidae) and Charidotis auroguttata (Coleoptera: Chrysomelidae: Cassidinae). With the exception of A. notatus, all agents were approved for release and exhibited promising rates of establishment and damage at a number of field localities (King et al., 2011).<br>

Source: cabi.org
Description

P. aquatica forms strong perennial clumps (unless kept grazed), 60-200 cm tall, arising from short knotted rhizomes. Shoots are swollen and tuberous at their bases. Flower stems have smooth internodes. Leaf sheaths are rounded on the back, firm, hairless, light brown or brownish-green. Ligules are 4-9 mm long, membranous, rounded. The leaf blade is hairless, green, tapered to a long fine point, 15-60 cm long, 5-11 mm wide, flat, smooth on the under surface, slightly rough on the margins. The inflorescence is a dense, stiff, cylindrical, spike-like panicle, oblong or slightly tapered top and bottom, 3.5-12 cm long, 0.8-2.5 mm across;main axis smooth, branches hidden. Spikelets are light green, 4.5-6.5 mm long, with two lower sterile florets and an upper fertile one, breaking above the glumes at maturity (from Champion et al., 2012).

Impact

P. aquatica, a perennial grass which can form large clumps and has short rhizomes around the base, has been extensively used as a pasture forage plant. From its native range around the Mediterranean it has been introduced to several parts of the world, notably North America and Australia. In these countries it has been sown as a pasture species or for revegetation after burning, and has naturalized and spread widely. It outcompetes and displaces native plant species. Tall stands of dry foliage present a fire risk in summer. In Australia it is regarded as an environmental weed in Victoria, New South Wales and South Australia, and as a priority environmental weed in three Natural Resource Management regions.

Hosts


In California, P. aquatica outcompetes and displaces native plant species (Harrington and Lanini, 2000). Where it occurs in Australia it presumably also replaces native grasses and other plants in the areas it invades.

Biological Control
<br>Since P. aquatica is a valuable pasture species, any attempts at biological control are not likely to be welcomed by farmers.

Source: cabi.org
Light Black spot
Description

Non-breeding individuals are dark olive on top and light olive to yellow-brown on the sides, often with an allochrous blue sheen. The chest is pinkish and lips are bright green. Breeding individuals are shiny dark green on the top and sides, red and black on the throat and belly, and have obvious vertical bands on the sides. Six to seven dark vertical bars cross two horizontal stripes on the body and caudal peduncle. Fins are olivaceous. They are covered in yellow spots with the dorsal and anal fins displaying an outline of a thin orange band. Caudal fins are often grey with pale interstices and dots covering the entire fin. Redbelly tilapia usually weigh 300 g and can be up to 40 cm in length with a total of 13 to 16 dorsal spines. Adults show a black spot outlined in yellow. Redbelly tilapia individuals that are from 2 to 14 cm standard length (SL) have an entirely yellow to grey caudal fin with no dots, developing a greyish caudal fin with dots with increasing size (Williams and Bonner, 2008, Froese and Pauly, 2014).

Biological Control
There is potential to use the natural enemies reported from its native range to control redbelly tilapia.

Source: cabi.org
Light Black spot
Description

P. bivittatus is a very large (6 m total length), heavy-bodied snake (175 kg), although the figures on maximum size are disputed and/or based largely on captive specimens (Murphy and Henderson 1997, Barker et al. 2012;see next paragraph for more detail). Females grow larger than males. As with many pythons, several scales on the snout contain obvious heat-sensing pits. The body has dark, black-bordered, brown dorsal and lateral blotches separated by tan coloration that extends to the belly;a dark triangular region or spearhead on top of the head;a white line that extends posteriorly under the eye;and a light-coloured belly bordered by black spots. Considerable variation exists among individuals, and several aberrant colour ÔmorphsÕ (albino, ÔgreenÕ, ÔgraniteÕ, ÔlabyrinthÕ, etc.) have been produced by reptile breeders (information in this paragraph compiled from https://www.cabi.org/isc/datasheet/66412#2F0653D0-4CC5-4891-9E04-CF59503..." Smith, 1943;https://www.cabi.org/isc/datasheet/66412#F93D0674-4360-4497-99A3-5CF4402..." Groombridge and Luxmoore, 1991;https://www.cabi.org/isc/datasheet/66412#FC7B1E3C-3608-45F4-A7B0-D109FFD..." Walls, 1998;https://www.cabi.org/isc/datasheet/66412#FA65979E-3026-43BD-9DB7-34AA527..." Reed and Rodda, 2009).

Biological Control
<a href="https://www.cabi.org/isc/datasheet/66412#FA65979E-3026-43BD-9DB7-34AA527151EC" Reed and Rodda (2009) reviewed the utility of biological control for eradication of widespread populations of giant constrictors, including P. bivittatus. They concluded that no such tools are available for snakes despite extensive research efforts for Brown Treesnakes (Boiga irregularis) and other known invaders, and that the track record of biocontrol for vertebrate invaders is dismal.

Source: cabi.org
Light Black spot
Description

R. catesbeiana is not the largest frog species in the world but it is one of the top ten (and the largest true frog in North America) with a maximum body length slightly in excess of 200 mm (typical length 90-152 mm) and body weight up to 0.5 kg. Like most frogs, it undergoes a drastic metamorphosis during its life cycle, passing from a young aquatic life phase with branchial respiration, predominantly plankton feeding, iliophagous or herbivorous, to reach adult life as an animal with pulmonary and skin respiration and a carnivorous feeding habit (Teixeira et al., 2001). Bullfrog tadpoles are also very large by frog standards (80-150 mm) and can take from 12 to 48 months to reach metamorphosis. A bullfrog tadpoleÕs body can be as large as a golf ball with a relatively long, high-finned and muscular tail. The colouration of the tadpole stage is brown to light olive with small black spots scattered across the head and upper body. At metamorphosis the tadpoles resorb their gills and finned tails while transforming into juvenile miniatures of adult bullfrogs but without secondary sexual characters. The colour of adults varies from olive, green or brownish on the dorsum with vague spots or blotches;the head is lighter green, and the legs blotched or banded;the eardrums are conspicuous. The hind feet are fully webbed. The skin is mostly smooth. There are no dorsolateral folds;a short fold extends from the eye over and past the eardrum to the forearm.


Source: cabi.org
Description

A. nigrofasciata is a fairly small cichlid that grows to approximately 12 cm but more commonly to 8.5 cm in length (Page and Burr, 1991;Froese and Pauly, 2014). It is pale blue/grey in colour with approximately seven black vertical stripes/bars on the sides that extend onto the dorsal and anal fins. The vertical stripes vary in intensity and the first and third bar may appear as blotches. The first or second bar may be Y shaped. There is a black spot on the operculum. The fins are clear or light blue/grey. Large males may have intense black bars with long fin rays at rear of dorsal and anal fins (Page and Burr, 1991). Selective breeding has produced several colour variations including pink, albino, long-finned and marbled (Page and Burr, 1991).

Impact

A. nigrofasciata is a small, popular ornamental freshwater fish that is native to a number of countries in Central America. It occurs as an introduced species in the aquatic habitats of at least 10 countries, principally because of human-mediated translocation and release. Due to the popular ornamental status of A. nigrofasciata, it is rarely considered a “pest” species. Wide environmental tolerances, the ability to colonise disturbed habitats, trophic opportunism, parental care and fast growth rates all contribute to the likelihood of this species becoming invasive. Potential ecological impacts upon endemic fish fauna may include resource competition and predation of aquatic invertebrate communities as a whole. Research has suggested that A. nigrofasciata may be responsible for the displacement of native fishes in Mexico and Hawaii. Of particular note is that the species is aggressive, particularly when breeding as territories are established on the substrate and defended against all intruders.


Source: cabi.org
Light Acer negundo
Title: Acer negundo
Description

A. negundo is an often multi-stemmed tree reaching a height of no more than 20 m and a stem diameter of up to 1 m (Rosario, 1988). In more open vegetation the canopy usually exhibits a broad and open crown and may even become shrubby, whereas in the face of competition in a forest stand the trunk tends to be single-stemmed and straighter. Shoots are green and turn violet in the second year. The bark is grey-brown becoming dark grey and is shallowly cracked. Buds are opposite, small, 2-5 mm, two-scaled and silky white. The leaves are 15-35 cm long, pinnate with 3-5 (or 7) leaflets and light green but paler below. The leaflets are lobed and serrated. Leaflet shape is variable, for instance in var. interior the first pair of leaflets is 3-lobed. Male flowers are born in corymbs with pendent stamens whilst female flowers are in small pendent racemes. Both types of flowers are small and pale yellowish-green in colour. There is much variation in the morphology of pistillate flowers with the presence of stamens on a proportion of the flowers (Hall, 1951). The fruit consists of two fused winged samaras to 4 cm long, diverging at an angle of less than 60 degrees. The samaras separate when shed and contain a single wrinkled seed.

Impact

A. negundo is a small and variable tree of little economic value native to much of North America. It has been widely planted mainly for amenity purposes in non-native parts of North America, Europe and Asia where it is now regenerating freely and spreading, invading riparian zones and urban areas. In the temperate parts of the southern hemisphere the spread of A. negundo is more limited. Although this pioneer species is invasive throughout much of its introduced range, actual impacts are not great. This species has no important negative impacts on human activities. In natural habitats the species becomes an important component of the vegetation in riparian systems and increases siltation.

Hosts


Some abandoned pastures, for instance in Poland, are readily colonized by A. negundo (Falinski, 1998). It is an occasional invader of cropland and forested areas including plantations.


Source: cabi.org
Title: Acer negundo
Description

A. fuchsiae is a typical eriophyid mite with a wormlike or fusiform body, colour in life light yellowish-white (CABI/ EPPO, 1997). The adults are very small mites bearing only two anterior pairs of legs. The adult females measure 200-250 µm in length and 55-60 µm in width. In eriophyoids, the males are slightly smaller than the females. Morphological observation of the short and acuminate anterior shield lobe over the rostrum, which is truncate underneath, plus the granules on the shield surface that obscure the shield pattern on the rear part of the shield, characterize this species. The adult female stage morphological description is described by Keifer (1972).

Recognition

Look for any variation in coloration of the plant. The leaves start to redden and as populations of the mite increase, the leaves and flowers are deformed or galled. New galled leaf tissue is pale-green and rusted, and becomes reddened with time. Symptoms of infestation are most strongly expressed on the terminal shoots, and heavy infestation can stop all new growth. Examination with a hand lens should reveal the presence of the mite.

Symptons

Infestation causes rusting and deformation of the leaves, galls becoming grotesquely swollen and blistered. The deformed tissues develop russeting or become reddened. These symptoms are most strongly expressed on the terminal shoots. The leaf galls resemble those of peach leaf curl (Taphrina deforans). Later the flowers become deformed and at the end all new growth ceases (CABI/ EPPO, 1997).

Impact

A. fuchsiae, the fuchsia gall mite, is native to South America. It was first found in California, USA in 1981 where it has spread rapidly, and more recently it has invaded Europe since 2003, and it is a declared quarantine pest in both. It attacks only fuchsia (Fuchsia spp.), but once established it is very difficult to eradicate and impacts can be so severe that some growers in California have given up growing the plants entirely.

Hosts

A. fuchsiae is the only species of Eriophyidae developing on Fuchsia spp. Anderson and MacLeod (2007) state that m ore than 100 Fuchsia species are recorded mostly native to Central and South America, but also New Zealand and Tahiti with thousands of cultivars. However, only a relatively small number of these have been evaluated for their susceptibility to this pest. Those tested can be divided into groups based on their resistance to attack by the mite, into: very sensitive, sensitive, and resistant to highly resistant (Koehler et al., 1985). Very sensitive: species: Fuchsia magellanica;cultivars: Angel Flight, Bicentennial, Capri, Chiona Doll, Christy, Dark Eyes, Display, Firebird, First Love, Golden Anne, Jingle Bells, Kaleidoscope, Kathy Louise, Lisa, Louise Emershaw, Manrinka, Novella, Papoose Raspberry, South Gate, Stardust, Swingtime, Tinker Bell Troubadour, Vienna Waltz, Voodoo, Walz Bella, Westergeist. Sensitive: species: Fuchsia arborescens, Fuchsia denticulate, Fuchsia gehrigeri, Fuchsia macrophylla, Fuchsia procumbens, Fuchsia triphylla;cultivars: Dollar princess, Englander, Golden West, Lean, Macchu Picchu, Pink Marschmallow, Postijon, Psychedelic. Resistant to highly resistant: species: Fuchsia boliviana, Fuchsia microphylla, Fuchsia microphylla ssp. h indalgensis, Fuchsia minutiflora, Fuchsia radicans, Fuchsia thymifolia, Fuchsia tincta, Fuchsia vensusta;cultivars: baby Chang, Chance Encounter, Cinnabarina, Isis, Mendocino, Miniature Jewels, Ocean Mist, Space Shuttle.
Host Plants and Other Plants Affected
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Plant name|Family|Context
Fuchsia|Onagraceae
Fuchsia arborescens|Onagraceae
Fuchsia boliviana|Onagraceae|Unknown
Fuchsia denticulata|Onagraceae
Fuchsia gehrigeri|Onagraceae
Fuchsia macrophylla|Onagraceae
Fuchsia magellanica (Magellan fuchsia)|Onagraceae
Fuchsia microphylla|Onagraceae|Unknown
Fuchsia minutiflora|Onagraceae|Unknown
Fuchsia procumbens|Onagraceae
Fuchsia radicans|Onagraceae|Unknown
Fuchsia regia subsp. serrae|Onagraceae|Unknown
Fuchsia thymifolia|Onagraceae|Unknown
Fuchsia triphylla|Onagraceae|Unknown
Growth Stages
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Flowering stage, Vegetative growing stage
Symptoms
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Infestation causes rusting and deformation of the leaves, galls becoming grotesquely swollen and blistered. The deformed tissues develop russeting or become reddened. These symptoms are most strongly expressed on the terminal shoots. The leaf galls resemble those of peach leaf curl (Taphrina deforans). Later the flowers become deformed and at the end all new growth ceases (CABI/ EPPO, 1997).


Source: cabi.org
Description

Evidence for a Viral Agent
A virus, BBTV, is the causal agent of bunchy top disease of banana. Although unequivocal evidence by reproduction of the disease through inoculation of purified virions or cloned genomic components is lacking, definitive association of BBTV with bunchy top disease was demonstrated by insect vector-mediated transmission of BBTV from an infected banana to a healthy banana plant. The virions are intimately associated with the disease (Harding et al., 1991;Thomas and Dietzgen, 1991) and have been detected in all symptomatic plants tested (Dietzgen and Thomas, 1991;Thomas, 1991;Thomas and Dietzgen, 1991;Karan et al., 1994;Kumar et al., 2011). Dale et al. (1986) and an published study (ML Iskra-Caruana, Montpellier, France) isolated dsRNA, suggestive of luteovirus infection, from Cavendish cultivars and from bunchy top affected plant samples. However, neither these, nor any subsequent studies, have identified or established a role for any virus other than BBTV in banana bunchy top disease aetiology.
Particle and Genome Properties
The virions of BBTV are icosahedra, ca 18-20 nm in diameter, have a coat protein of ca 20,000 Mr, a sedimentation coefficient of ca 46S and a buoyant density of 1.29-1.30 g/cm³ in caesium sulphate (Wu and Su, 1990c;Dietzgen and Thomas, 1991;Harding et al., 1991;Thomas and Dietzgen, 1991). Purified preparations have an A 260/280 of 1.33 (Thomas and Dietzgen, 1991). The virus possesses a multi-component genome, consisting of at least six circular, single-stranded DNA (ssDNA) components each ca. 1000-1100 nucleotides long, previously referred to as DNA-1 to -6 (Wu et al., 1994;Yeh et al., 1994;Burns et al., 1995;Xie and Hu, 1995). However, they were renamed as DNA-R, -U3, -S, -M, -C and -N. The DNA-R component encodes two open reading frames and other components each encode one protein (Burns et al., 1995;Dale et al., 1986;Beetham et al., 1997). Two areas of the non-coding regions are highly conserved between the six components (Burns et al., 1995). The first is a stem-loop common region of up to 69 nucleotides. It contains a nonanucleotide loop sequence conserved amongst ssDNA plant viruses and which may be involved in rolling circle replication and initiation of viral strand DNA synthesis. The second, 5' to the stem-loop common region, is a major common region varying in size between components from 65 to 92 nucleotides and which may have a promoter function. The initiation factor for endogenous DNA primers is also located within the major common region (Hafner et al., 1997a). DNA-R (c omponent 1) encodes a putative replication initiation protein and contains a second functional open reading frame internal to this, referred as U5, the function of which is unknown;whilst DNA-S (component 3) codes for the coat protein (Harding et al., 1993;Dale et al., 1986;Hafner et al., 1997b, Wanitchakorn et al., 1997). DNA-U3 (component 2) codes a protein of unknown function, DNA-M (component 4) codes for movement protein, DNA-C (component 5) has been shown to produce a gene product containing an LXCXE motif and to have retinoblastoma protein (Rb)-binding activity, known to perform cell-cycle-link protein, and DNA-N (component 6) codes for a nuclear shuttle protein. The gene product may be produced very early in the infection cycle and be responsible for switching the first infected cells to S-phase in preparation for virus replication. Recent research indicates that component 1 is the minimal replicative unit of BBTV and encodes the 'master' viral Rep (Horser et al., 2001a). Additional Rep encoding circular ssDNA components were reported in a few BBTV isolates from East Asia and the South Pacific region (Horser et al., 2001b). They were named BBTV-S1 and BBTV-S2, of 1109 and 1095 nts, and encoded a protein similar to the DNA-R segment but the genomic organization differed from that of DNA-R. The –S1 and –S2 components lack internal ORF U5, and the stem loop sequence was not similar to the six genomic components. These sequences were not considered as an integral part of the BBTV genome but the precise function of these additional DNAs was not known.
Strains of BBTV
Most isolates of BBTV are associated with typical severe disease symptoms. However, mild and symptomless isolates have been reported from Taiwan (Su et al., 1993;Djailo et al., 2016). BBTV has been confirmed in specimens of mild and symptomless infections from Taiwan by both ELISA and PCR (HJ Su, JL Dale and JE Thomas, Brisbane, personal communication, 1996) and the isolates can be transmitted by Pentalonia nigronervosa (HJ Su, Taipei, personal communication, 1996). Genomic differences, which correlate with these biological variants, have not yet been determined.
Two broad groups of isolates have been identified on the basis of nucleotide sequence differences between some, possibly all, of the six recognized genome components (Karan et al., 1994;Hu et al., 2007;Kumar et al., 2015;Qazi, 2016). The 'South Pacific' group (also referred as Pacific Indian Ocean (PIO) group) comprises isolates from Australia, Bangladesh, India, Myanmar, Pakistan, Sri Lanka, Fiji, Western Samoa, Tonga, Hawaii (USA) and all the isolates identified, as of 2017, in Africa (Angola, Benin, Burundi, Cameroon, CAR, Congo, DRC, Egypt, Equatorial Guinea, Gabon, Malawi, Nigeria, Rwanda, South Africa and Zambia), whilst the 'Asian' group (also referred as Southeast Asian (SEA) group) comprises isolates from China, Indonesia, Japan, the Philippines, Taiwan, Thailand and Vietnam. These differences are present throughout the genomes of components 1 and 6, but are most striking in the untranslated major common region. No biological differences have been associated with these sequence differences.
Magee (1948) noted that certain plants of 'Veimama', a cultivar originally from Fiji and growing then in New South Wales, showed a 'partial recovery' from bunchy top symptoms and produced bunches. After an initial flush of typical severe symptoms in three or four leaves, subsequent leaves showed few, if any, dark-green flecks. Suckers derived from these partially recovered plants also displayed a flush of typical symptoms followed by partial recovery. The origin of the infection, whether from Australia or Fiji, was uncertain. This partial recovery was noted for some infected plants of 'Veimama' only, and in Fiji was noted for one sucker only on a single infected stool from among hundreds of infected stools of 'Veimama' observed. Magee was not able to transmit the virus from partially recovered plants and was only able to super-infect them, with difficulty, with high inoculum pressure. This may be an example of a mild strain of BBTV, possibly a non-aphid transmitted one, propagated vegetatively, reaching only a low titre and conferring a degree of cross-protection. Alternatively, 'Veimama' may not be uniform and individual plants with a degree of resistance may exist. The complete explanation for this phenomenon is unclear. Evidence from recent studies suggests the occurrence of Musa cultivars with variable response to BBTV infection, ranging from extreme to moderate susceptibility and recovery associated with reduced virus titre (Ngatat et al., 2017;PL Kumar, IITA, Nigeria, personal communication, 2017). It is likely that previous observations of mild symptoms and lack of aphid-transmission may be related to virus-host interaction rather than to mild strains.
The inability to transmit bunchy top from abacá to banana (Ocfemia and Buhay, 1934) was originally considered evidence that two distinct strains of the virus existed. However, recent studies have identified a new virus, Abaca bunchy top virus (ABTV) which also belongs to the genus Babuvirus, as the cause of bunchy top-like symptoms in abacá (Sharman et al., 2008). The possibility of co-infection or single infection of BBTV and ABTV in abacá cannot be ruled out in endemic regions.

Symptons

The typical symptoms of bunchy top of banana are very distinctive and readily distinguished from those caused by other viruses of banana. Plants can become infected at any stage of growth and there are some initial differences between the symptoms produced in aphid-infected plants and those grown from infected planting material.
In aphid-inoculated plants, symptoms usually appear in the second leaf to emerge after inoculation and consist of a few dark-green streaks or dots on the minor veins on the lower portion of the lamina. The streaks form 'hooks' as they enter the midrib and are best seen from the underside of the leaf in transmitted light. The 'dot-dash' symptoms can sometimes also be seen on the petiole. The following leaf may display whitish streaks along the secondary veins when it is still rolled. These streaks become dark green as the leaf unfurls. Successive leaves become smaller, both in length and in width of the lamina, and often have chlorotic, upturned margins. The leaves become dry and brittle and stand more erect than normal giving the plant a rosetted and 'bunchy top' appearance.
Suckers from an infected stool can show severe symptoms in the first leaf to emerge. The leaves are rosetted and small with very chlorotic margins that tend to turn necrotic. Dark-green streaks are usually evident in the leaves.
Infected plants rarely produce a fruit bunch after infection and do not fruit in subsequent years. Plants infected late in the growing cycle may fruit once, but the bunch stalk and the fruit will be small and distorted. On plants infected very late, the only symptoms present may be a few dark green streaks on the tips of the flower bracts (Thomas et al., 1994).
Mild strains of BBTV, which induce only limited vein clearing and dark-green flecks, and symptomless strains have been reported in Cavendish plants from Taiwan (Su et al., 1993). Mild disease symptoms are expressed in some banana cultivars and Musa species. The dark-green leaf and petiole streaks, so diagnostic and characteristic of infection of cultivars in the Cavendish subgroup, can be rare or absent (Magee, 1953). Some plants of 'Veimama' (AAA, Cavendish subgroup), after initial severe symptoms, have been observed to recover and to display few if any symptoms.

Impact

BBTV is the most serious virus disease of bananas and plantains. It occurs in Africa, Asia, Australia and South Pacific islands. The virus is transmitted in a persistent, circulative, non-propagative manner by the banana aphid, Pentalonia nigronervosa, which has worldwide distribution. The virus is also spread through infected planting material. All banana cultivars are thought to be susceptible, with no known sources of resistance.

Hosts

In the Musaceae, BBTV is known to infect a range of Musa species, cultivars in the Eumusa (derived mainly from M. acuminata and M. acuminata x M. balbisiana) and Australimusa (derived mainly from M. maclayi, M. lolodensis and M. peekelii) series of edible banana and Ensete ventricosum (enset). Susceptible Musa species include M. balbisiana (Magee, 1948;Espino et al., 1993), M. acuminata ssp. banksii, M. textilis (abacá) (Magee, 1927), M. velutina (Thomas and Dietzgen, 1991), M. uranoscopos, M. jackeyi, M. ornata and M. acuminata ssp. zebrina (ADW Geering and JE Thomas, Brisbane, personal communication, 1998).
To date, there are no confirmed reports of immunity to BBTV in any Musa species or cultivar. However, differences in susceptibility between cultivars subject to either experimental or field infection have frequently been noted (Magee, 1948;Muharam, 1984;Espino et al., 1993;Ngatat et al., 2017).
Espino et al. (1993) evaluated a total of 57 banana cultivars for their reaction to bunchy top, both by experimental inoculation and field observations. All cultivars in the AA and AAA genomic groups were highly susceptible. However, low levels of infection (as assessed by symptom expression) or total absence of symptoms following aphid inoculation was noted in some cultivars containing the B genome. These included 'Radja' (AAB, syn. 'Pisang Raja' - 12.5% of inoculated plants with symptoms), 'Bungaoisan' (AAB, Plantain subgroup - 0%), 'Pelipia' (ABB, syn. Pelipita' - 10%), 'Pundol' (ABB - 0%), 'Katali' (ABB, syn. 'Pisang Awak' - 0%), 'Abuhon' (ABB - 0%) and 'Turangkog' (ABB - 0%).
These cultivars were not back-indexed by aphid transmission to a susceptible banana cultivar or tested biochemically (for example, by ELISA), so the presence of symptomless infection cannot be ruled out. Also, greater numbers of aphids than the 15 used here may have resulted in infection. Cultivars 'Abuhon' and 'Bungaoisan' are susceptible to BBTV by experimental aphid inoculation (ADW Geering and JE Thomas, Brisbane, personal communication, 1998). Nevertheless, it appears that real differences exist in cultivar reaction to bunchy top and the time taken before symptoms are expressed.
Evaluation of 16 Musa genotypes in Cameroon comprising plantain landraces, Cavendish bananas and synthetic hybrids revealed a high level of tolerance to BBTV in Gros Michel (AAA, Cavendish sub-group) and Fougamou (ABB cooking banana) (Ngatat et al., 2017). In another study of 40 Musa genotypes in Burundi, 8 genotypes (Musa balbisiana type Tani (BB), Kayinja (ABB), FHIA-03 (AABB), Prata (AAB), Gisandugu (ABB), Pisang Awak (ABB), Saba (ABB) and Highgate (AAA, Gros Michel subgroup)) were found to be asymptomatic, although Pisang Awak, Saba and Highgate tested positive to virus indicating tolerance to BBTV in some genotpyes (Niyongere et al., 2011).
Cultivars within the Cavendish subgroup form the basis of the international banana export trade and are generally highly susceptible to bunchy top. However, it appears that not all cultivars with an AAA genome are similarly susceptible. 'Gros Michel' exhibits resistance to the disease under both experimental inoculation and field conditions and Magee (1948) considered that the introduction of this cultivar to Fiji in the early 1900s contributed to partial rehabilitation of the bunchy top-devastated industry. Compared to 'Williams' (AAA, Cavendish subgroup), the concentration of virions of BBTV in infected plants of 'Gros Michel' and the proportion of plants infected by aphid inoculation is lower. Symptoms are also slower to develop and are less severe (Ngatat et al., 2017;ADW Geering and JE Thomas, Brisbane, Australia, unpublished, 1997). These factors may contribute to a reduced rate of aphid transmission and field spread in plantations of 'Gros Michel' (Ngatat et al., 2017).
There is no evidence for hosts outside the Musaceae, though reports have been conflicting. Su et al. (1993) obtained positive ELISA reactions from BBTV-inoculated Canna indica and Hedychium coronarium, and recovery of the virus to banana, though not reported here, was demonstrated (HJ Su, Taipei, personal communication, 1996). Ram and Summanwar (1984) reported Colocasia esculenta as a host of BBTV. However, Hu et al. (1996) were unable to demonstrate C. esculenta or Alpinia purpurata as experimental (E) or natural (N) hosts of BBTV in Hawaii. Geering and Thomas (1996) also found no evidence for the following species as hosts of BBTV in Australia: Strelitzia sp. (N), C. indica (E, N), C. x generalis (N), C. x orchiodes (N), H. coronarium (E), Helocania psittacorum (E), Alpinia coerulea (E, N), A. arundinelliana (E), A. zerumbet (E), Alocasia brisbaensis (E, N) or C. esculenta (E, N). Magee (1927) was unable to infect Strelitzia sp., Ravenala sp., Canna sp. (including C. edulis), Solanum tuberosum and Zea mays. Since the advent of improved and reliable diagnostics for BBTV, searches for alternative hosts outside the Musaceae, including those earlier suspects, have turned out to be negative.
Primary hosts are banana cultivars derived from M. acuminata and M. acuminata x M. balbisiana, and Musa textilis (abacá).


Source: cabi.org
Description

C. terniflora is a climbing, semi-evergreen, woody vine (Swearingen and Bargeron, 2016). Stems are 3-6 m, climbing with tendril-like petioles and leaf rachises (Flora of North America Editorial Committee, 2018). Leaves are shiny, green and leathery (Missouri Botanical Garden, 2018), and are opposite, compound, with 3-5 leaflets of 5-7.5 cm and margins entire (Swearingen and Bargeron, 2016). Leaflets are ovate or broadly lanceolate to narrowly deltate (Flora of North America Editorial Committee, 2018). Inflorescences are axillary 3-12-flowered cymes (or compound cymes or paniculate with cymose subunits) (Flora of North America Editorial Committee, 2018). Flowers are 1.4-3.0 cm in diameter (Flora of China Editorial Committee, 2018), bisexual often with some unisexual flowers in the same inflorescence, with pedicels of 1-3.5 cm (Flora of North America Editorial Committee, 2018). Flowers are fragrant with four slender white petal-like sepals (Swearingen and Bargeron, 2016) that are obovate-oblong and measure 5-15 x 2-6 mm (Flora of China Editorial Committee, 2018). Flowers have up to 50 stamens and 5-10 unicarpellate pistils (Flora of North America Editorial Committee, 2018). The ovary is superior (Burnham, 2013). Seeds are enclosed in flattened achenes, production is prolific, and seed heads have long, silvery-grey, feather-like hairs (Swearingen and Bargeron, 2016). Each achene has a plume attached (Mahr, 2017), and this helps with wind dispersal (Burnham, 2013). The mature bark is light brown and shreds longitudinally (Burnham, 2013).

Impact

Clematis terniflora is a perennial woody vine, native to Asia and introduced to North America as an ornamental. It can self-seed, and has escaped cultivation and naturalized in many parts of the USA. It is reported to be invasive in a number of eastern states. It grows in forest margins, scrub, grassy areas on hills and slopes, and in disturbed areas such as roadsides, thickets and urban green spaces. Seeds are widely dispersed by wind. It grows rapidly, forming dense clumps that outcompete and cover young native trees, shrubs and herbs at ground level and suppress seed germination. It can also climb to nearly 10 m, smothering trees and pulling down telephone poles. C. terniflora is difficult to control. Removal by hand can help encourage the growth of native species, but is unlikely to eliminate C. terniflora entirely due to root re-sprouting and prolific seed production. Some herbicides have proven effective in controlling the spread of this species;however, repeated applications are necessary.


Source: cabi.org
Description

A cactus-like, usually leafless but evergreen shrub or small tree up to 5 metres high and 15-20 cm in trunk diameter, with fleshy or succulent stems, much branched, hairless throughout, producing abundant milky sap when injured. Stems with whorls of branches nearly to base but on large plants shedding the spiny tissue and developing a rounded brown, fissured trunk. The 3-angled (sometimes 4-angled) branches are mostly joints 10-30 cm long and 2-5 cm across, slightly shiny dark green, with yellowish or whitish streak in the groove of the axis between the angles. The soft cut branches have a light green outer layer less than 0.5 cm thick, which yields latex, and within whitish watery tissue, slightly bitter. Raised leaf bases 0.5 cm high and about 1-2.5 cm apart along the edges of branches correspond to nodes and bear paired spreading gray spines (stipules). Leaves few, scattered, alternate, minute, stalkless, rounded, slightly shiny green, succulent, slightly thick and shedding early, or absent. Flowers small, yellowish green, borne intermittently in small clusters along the stem’s edge (Little et al., 1974).

Impact

E. lactea has been widely commercialized as an ornamental plant and due to the presence of spines it is also used as a fence/hedge plant. Many cultivars have been developed for the horticultural trade (USDA-ARS, 2016). It has escaped from cultivation and once naturalized, it often grows forming thickets mostly in disturbed sites, abandoned gardens, deciduous forests, coastal forests, and along roadsides (Little et al., 1974;PIER, 2016;PROTA, 2016). E. lactea spreads by seeds and vegetatively by cuttings and stem fragments (Little et al., 1974). Currently, this species is listed as invasive in Hawaii and Cuba (Oviedo Prieto et al., 2012;PIER, 2016). In Puerto Rico and the Virgin Islands, it is spreading and forming thickets in some places (Little et al., 1974).


Source: cabi.org
Description

Trees or shrubs, producing abundant milky latex when injured, 2-6 m tall, dioecious, eventually forming a trunk 10-25 cm DBH with rugose, gray or light bark. Stems green, succulent, finely, longitudinally striate. Leaves alternate, present only on new growth;stipules very small, caducous;petiole ± absent;leaf blade oblong-linear, 7-15 × 0.7-1.5 mm, base attenuate, margin entire, apex obtuse. Cyathia clustered at apex of branches, pedunculate, unisexual;involucral leaves minute, membranous, caducous;involucre turbinate, approximately 2 × 1.5 mm, shortly pubescent inside;glands 5, peltate-ovate or subrounded. Male flowers many, exserted from involucre. Female flower: ovary glabrous, exserted from involucre;styles connate below middle;stigma 2-lobed. Capsule 3-lobed, 8 × 8 mm, smooth, sparsely pilose or glabrous. Seeds ovoid-globose, 4 × 4 mm, smooth;caruncle small (Flora of China Editorial Committee, 2016).

Impact

E. tirucalli is a many-branched succulent plant widely commercialized as an ornamental, hedge plant, potted plant and for soil conservation (Orwa et al., 2009;USDA-ARS, 2016). It has escaped from cultivation and once naturalized, it often grows forming thickets mostly in disturbed sites, abandoned gardens, deciduous forests, semiarid sites, and along roadsides (Little et al., 1974;PIER, 2016). This species grows very fast, and produces a lot of biomass even under very marginal soil and extreme climatic conditions (Mwine and Damme, 2011). In invaded areas, it is propagating vegetatively by cuttings and stem fragments (Little et al., 1974;PIER, 2016). Currently, this species is listed as invasive in Hawaii and Cuba (Oviedo Prieto et al., 2012;PIER, 2016), but is listed as potentially invasive on many islands in the Pacific and in tropical and subtropical areas of Asia (Nguyen and Sosef, 1999;Flora of China Editorial Committee, 2016;PIER, 2016).


Source: cabi.org
Description


IYSV is a tospovirus, similar to the type species of the genus, Tomato spotted wilt virus (TWSV). The virus particles of IYSV are protein-enveloped RNAs and consist of three genomic RNA segments: Large (L), Medium (M) and Small (S). The entire genome codes for six essential proteins via five different open reading frames. The L RNA is negative-sense coding for a polymerase, the M RNA codes for two glycoproteins (GN and GC) and a non-structural protein (NSm), and S RNAs are ambisense and code for the nucleocapsid (N) and the non-structural (NSs) proteins (Pappu et al., 2008). The three RNAs are tightly linked with the N protein to form ribonucleoproteins (RNPs). The RNPs are encased within a lipid envelope (Pappu et al., 2009). Serological divergence exists among tospoviruses, and little cross reaction among antisera is observed (Pozzer et al., 1999). PCR based detection is possible and is used for diagnostics.

Recognition


Where IYSV infection is suspected, samples should be sent to a diagnostic laboratory for ELISA and PCR testing. The distribution of IYSV within an infected plant is uneven and samples should be taken in close proximity to the lesion (Gent et al., 2006;Pappu et al., 2008).
There is evidence to suggest that iris yellow spot (or a disease causing similar symptoms) may also be cau